from Listeria !,v~novii and of /so from Listeria
Transcription
from Listeria !,v~novii and of /so from Listeria
Biodrimica et Biop/rysica Acta, 1130 ( 1992) 81-84 © 1992 Elsevier Science Publishers B.V. All rights reserved 0167-4781/92/$05.00 81 Short Sequence-Paper BBAEXP 90320 Listeriolysin genes: complete sequence of ilo from Listeria !,v~novii and of /so from Listeria seeligeri Albert Haas 1 , Martina Dumbsky and Jürgen Kreft Institut fiir Genetik 1md Mikrobiologie. U~ril'ersität Wiirzhurg, Würzburg (German_\') ( Received 11 December 1991 ) Key words: Thiol-activated cytolysin; Listeriolysin 0; Cysteim: motif; ( l.. irmwrii ): ( L .\'('t'lig(•ri) The completc DNA scqucnccs coding for thc thiol-activutcd cytolysins fmm /..i.'itericl inmol'ii. ivanolysin 0 <ILO) and for sccligerolysin 0 (LSO) from Listeritl seeligel'i havc bccn dctcrmincd. Thc dcduccd amino acid scqucnccs rcvcalcd that: (i) thc primary translation products comprisc 528 (JLQ) and 530 (LSO) amino acids. rcspcctivcly. (ii) ILO c,mtains two c~·stcincs. L.SO has u substitution in thc conscrvcd cystcinc motif. The thiol-activated cytolysins are a family of poreforming toxins from diverse genera of Gram-positive bacteria [16], most of which are secreted into the extracellular medium. These toxins include the species-specific types of Iisteriolysin 0 produced by the three Listeria species which are hemolytic on blood agar: Listeria monocytogenes (pathogenic for man anct animals), Listeria ivanoL·ii (animal pathogen) and Listeria seeligeri (apathogenic). Their Iisteriolysins have previously bet!n characterized biochemically [6,10],and it has also been shown that they vary in cytolytic activity. The gene for Iisteriolysin 0 (h/y) from 1.4. monocytogenes has been cloned and sequenced [4,13] and homologous DNA sequences have been detected in the chromosome of the two other hemolytic Listeria species [11]. lt has been firmly established, that Iisteriolysin 0 (LLO) is an essential virulence factor of L. monocytogenes (reviewed in Refs. 2 and 3), which enables this facultative iiltracellular parasite [2,5] to escape from the phagosome of the invaded mammalian cell, e.g., macrophages or other phagocytes. L. ir:anol'ii has also been shown to replicate intracellularly, whereas the avirulent L. seeligeri does not [5,8]. The sequence data reported in this paper have been submitted to the EMBL/Genbank Data Libraries under the accession numbers X60461 (i/o) and X60462 (/so). 1 Present address: UCLA. Molecular Biology Institute. 405 Hilgurd Ave., Los Angeles, CA 90024-1570. USA. Correspondence: J. Kreft, (from 16 March 1992 on) Biozentrum der Universität Würzburg, Lehrstuhl Mikrobiolosie, Am Hubland. W8700 Würzburg, Germany. We have established genomic DNA Hbraries of L. see/igeri (SLCC3379) and L. iL·anol'ii (ATCCI9119) by ligating chromosomai DNA fragments from partial Sau3A digests ( L. il'allot·ii) or size-fractionated Hindill digests ( L. seeligeri) into the plasmid vector pTZ 18R [12]. Transformed recombinant E. coli DH5-a clones were screened by colony hybridization for homology to a h/y-specific gene probe (651 bp Hindill fragment from pLM47, Ref. 11 ). One of the positive clones yiclded plasmid pAHA9, which by DNA sequcncing with the didcoxy chain termination mcthod was shown to contain the completc determinant (/!J·o) for Iisteriolysin 0 from L. seeligeri, termcd seeligerolysin 0 (LSO) (Fig. 1). Among more than 15000 recombinants from the L. il'anor·ii library, three positive clones were identified which contained overlapping inscrts of dif· ferent sizes, but which were too small to span the entire Iisteriolysin gene. The DNA sequence from all three recombinants was determined. The largest insert (from pAHAlO) included 1029 base pairs from the carboxy-terminal moiety of the gene (i/o) for listeri· olysin 0 from L. il'anol'ii, ivanolysin 0 (ILO). The other two independent inserts contained shorter segments from the identical ilo sequence. For both pAHA9 and pAHAlO the Iisterial origin of the inscrted DNA was confirmed by Southern hybridization. Several at· tempts to detect the complete ilo gene in the genc bank failed, but by the polymerase chain-reaction (PCR) we could isolate, clone into pTZJ8R and sequence the complete detcrminant (Fig. 1). The PCR· primer for the 5' rcgion was dcduced from a previously determined upstream sequence (Kreft and Weber, unpublished). in addition the complete lsp gene was 82 mo11ocytogenes [4,13]. ILO, LSO and LLO are highly homologous: identity ILO /LLO 80%, LSO/LLO 82%, ILO jLSO 76%; similarity 91%, 90% and 86%, respectively, with rather heterogeneaus N-.termini. ILO shows one deletion at position 25 and LSO the insertion of one serine at position 33. The analysis of the predicted signal peptide of LSQ r~v~~,~~ Jb,,~-;. ~.~- ~i,n~.r~- . ~JllP:,:fi cantly frQm th~ cori:~sp()n.g~~g ·~Q. an{J. Lt~>.~·-~~~ quences: LSO Iacks one positive eilarge at position 3 (lle versus Lys) and has one hydrophobic amino acid less in the core region. Therefore, the LSO signal peptide might be less effective as an export..directing sequence. The most interesting findings from the analysis of the deduced protein sequences were: (i) that LSO has a non-conservative amino acid substitution (Phe versus reisolated by the same method in order to confirm the sequence data from the library. The DNA sequence homologies between ilojhly, lsojhly and üojlso were 78%, 77% and 76%, respectivel)\ The deduced amino acid sequences (Fig. 1) showed that the primary translation product of ilo is a s.28::'i\11li·p~:~~~.i~.:,;·Jl.f9~~1~<" 9f:x~~.~4J- .Q~,. that of /so comp~~S.!~·S~p;,arot·no~i,ä.qi~$::~($.9./lSltDa>~ We have previously d~tetmine.di . hie. }'l;ienninal amino. acid sequence of matufe Jit0::: [:10]~ therefore the signal peptide cleavage site for lU.C)? was placed after Ala-24. The N-termini of mature bSO• and LLO are not known, but signal peptides are preferentially cleaved after an alanine, which is also found in both LSO and LLO at position 24. The deduced amino acid sequences were compared (Fig. 2) to the deduced sequence for LLO from L. ls~ tJo la~ ATGAAAATATTtGGTTTAGTTATCATGTCGTTGCTATTTGTTAGTTTGGCAATAACACAACAACCTGAAGCGAGGGATGTCCCCGCGTACGATAGAAGCCAGGTGACTATATCTCCTGCT N 1C 1 r G L V 1 M I L L r V S L P 1 T 0 0 P E A R D V P A Y D R S E V T I S P A A~TAATGCTACTTTTAATr.ACATTGTTACTAGTAAGTTTACCGTTAGCACAAGAAGCTCAAGCA•·•~TGCCTCAGTATATAGTTAC•••CAAGGCATAATTTCACACATG N K K r N L L L MT Hpan (Jao} L.L- LV I S Hpan (.Uo) L p LA 0 Spill (lao) I A Q A CJal (.Uo) • DAS V Y S Y • Q G I 1 S H H CAAACACCACACTCCCCACCGGCAACACCAAAAACACCTGTAGAGAAAAACCA~CGGAAGAAATTAATAAATATATTTGGGGATTAAACTATGATAAAAATAGTA~GTCTATCAA I 'I' A PP P I P P A lt P IC 'I' P V E lC K ASPPAK P IC T P V E K K HA A H A E I 1 H K Y Q I D 0 Y I I N Y D IC H W G L S I 0 L D Y D IC N H I L V Y Q 120 40 114 38 240 80 234 Jlo GCACCACCAGCGTCTCCGCCTGCAAAGCCTAAGACG~GAAAAATGCAGCTCAAAfCGArcAATATATACAAGGGCTGCA'I'TATGATAAAAACAATATATTAGTGTACGAT ,: $0 GGTGAAGCAcrrTACAAACGTTC:CACCGAMAAGGGCTACAAAGATGGCAG'I'GAATA'!'ATTGTCC'I'TGAAAAAAAGAAAAAAGGTATC.U.TCAAAACAATGCAGACA'l"l'TCTGTCATMA'l' G I A V 'I' H V P P K K G Y K D G S I Y I V V I IC K K K G I H 0 H H A D I S V I N GGAGAAGC'I'CTTAAAAATG'I'TCCACCAAAAGCAGGATACAAAGAAGGAAA'l'CAATATATTC'l'AGTGGAGAAAAAGAAAAAATCTATC.U.TCAAAATAACGCAGATA'l"l'CAAGT'l'ATTAAC G I A V lC H V P P lC A G Y lC I G N 0 Y I V V E lC IC K 1C S I H 0 H H A D I Q V I H 360 120 354 118 GCAATTTCGAGCCTTACTTATCCTGGAGCGTTGGTAAAAGCAAATAGAGAATTAGTAGAAAATCAACCTAATGTA~tACCAGTAAAACGAGATTCACTTACATTAAGTGTAGATTTACCA 480 160 .i l o G LV Y D Ec:oRIUlo) lao .ilo J so J lo A 1 S 8 L 'I' Y P G A L V IC A H R I L V I H 0 P N V L P V lC R D I L 'l' L S V D L P TCGCTTGCAAGCCTTACTTATCCAGGAGCTTTAGTGAAGGCG.Ur2'CAGAGTTAGTCGAAAATCAACCCGATGTCCTCCCTGTGAAACGAGATTCAGTTACACTTAG'l'ATTGA'l"l'TGCCT S L A I L T Y P G A L V IC A H S I L V I H Q P D V L P V lC R D 8 V 'l' L S I D L P GGAATGACTAAAAAAGATAA'I'AAAATA'l'TC:GTTAAAAACCCTACAAAGTCAAACGTAAATAATGCCGTGAATACATTAGTAGAGCG'I"'J'GGAATGATAAGTATTCAAAAGCGTATCCTAAT G N 'I' K lC D H IC 1 P V IC N P T K 8 H V H N A V H T L V I R W H D IC Y S K A Y P M GGAA'J'GGTTAACCATGACAATGAAATAGTCG'l'TOAAAATGCAACTAAATCCAATATAAA'l'GACGGAGTGAATACTTTAGTAGATCG'l'TGGAATAATAAATACTCCGAAGAATACCCAAAT G N V N H D N I I V V Q N A T IC I H I N D G V N T L V D R W N N IC Y S E B Y P N lcoU(ilo) J•o J.lo t•o IJC! 78 474 158 100 2~ 594 198 ATTAATGCAAAAA'l'TGATTATTCCGATGAAA'I'GGCTTATAGTGAATCACAAT'l'AA'I'TGCCAAA'l'ftGGGACTGCCTTTAAAGCTCT'l'AATAATAG'1"1'TGAATGTAAAT'l"l"J'GAGGCAATT l N A IC I D Y I D I II A Y I I S 0 L l A 1t P G 'l' A P lC A V H H I L II V II r E A I A'M'ACTGCGAAAATTGACTAN.U'CMCAAATGGCCTATAGCGAATCGCAATTAGT'l'GCAAAA'I"'"'''GGTGCAGCATT'fAAACCTGT'l'AATAATAGTTTGAA'l'G'l'AAACTT'l'GGAGCCATT l I A 1C I D Y D Q I N A Y I I I Q L V A 1C P G A A F K A V H H S L H V II r G A I 714 ACITCIATGOOAAAGTACAAGAACAAC'l'CAT'J'AGT'I'TTAAGCAAA'I"I'TATTATAATAftAACGTTAATGAACCTACAAC:TCCTTCCAAA'l'TCI"1'TGGGGGTAGTGTTACCAAAGAACAAC'l'A I D G K V Q I I V l I P IC Q l Y Y N l N V H E P 'I' 8 P 8 lC r P G G 8 V '1' lC I 0 L AGTGAAGGTAAGGTGCAAGAAGAAGTTA'l"''AA'I"''TCAAACAAA'I"'"''ATTATAC'l'GT'l'AATG'l"l'AATGAACCTACAAGCCCTTCCAGA'l"l'CT'Z'TGOTAAAAGTG'M'ACTAAAGAAAACTTG I I G lt V Q I I V I H P IC Q I Y Y 'I' V M V N I P 'I' 8 P 8 R P P G lC 8 V 'I' K I N L 840 280 8J4 278 720 240 l38 Nclei(Jlo) l•C# GATGCTT'I'AGGTGTAAA'I'GCCGAAAA'I'CC'I'CC'l'GCTTACATT'l'C'l'AG'l'GTTGCTTAeGGTCGCCAAG'l'TTATG'l'GAAACTA'l'CCTC'l'AGCTCGCATAG'l'AACAAAGT'l'AAAACTGC'l"rl'C D A L G V H P I M: P P A Y I I 8 V A Y G R Q V Y V IC L I 8 8 8 H 8 II 1C V I '1' A f llo CAACCGC'I'GGGCG1'AAA'I'GCGGAAAATCCACCCGCATACA'l'C'lC'l'AC'I'GTTGCAJ'UGGTCGTGACATT'l"l'CCTGAAAT'l'A'I'CGAC'l'AO'l"J'CACACAGCACCAGAGTGAAGGCTGCA'l"l'C Q A L G V M A I N P P A Y I I 8 V A Y G R D I r V lC L 8 'l' S S H S T R V IC A A r lao ilo GAOCICGGCGATGAG'l'GGCAAA'l'CAG'l'GAAACGGGA'I'G'l'AGAA'l"l'AACAAATA'l"l'ATAAAAAA'l":C'l'TCft'l'TAAAGCAG'l'CATT'l'A'l'GGTGGC'J'CAGCGAAAGAAGAGGT'l'GAAATTATT . I A A II I G I 8 V I G D V I L 'l' M I I K H I I P lC A V I Y G G 8 A K I B V I I I GA'l'GCTGCA'I'ftAAGGC'l'AAATCAGTTAAAGGTGATACAGAA'l"l'AGAAAATATTA'l"lCAAAATGCTTCA'l"l"l'AAAGCGG'l'GA'I"J"''A'l'GGTGGTTCAGCCAAAGATGAAGTAGAAATAATT D A A P IC G IC S V I G D V I L I II I I Q II A S P IC A V I Y G G S A K D B V I I I 1080 3110 GA'l'GGCAA'l"l"l'AGGCGAAC'l"'"CGAGATAft'l'TGAMAAAGGGKCACTTATGATAGAGAAAAeceTGGc:G'l"''C:CGATCTCGTACACAACTAACT'l"l"tTGAAAGATAA'I'GACTTAGCGGTT D G M L G I L R D I L IC IC G 8 'I' Y D R I M P G V P I I Y 'l' 'l' M P L 1C D II D L A V GA'I'GGAGA'l"l"l'AACCAAATTACGAGATA'l"'"l"lAAAACAAGGGGCTAA'l"l'T'l'GATAAGAAAAATCCGt:GCC'l'ACCCl\'I'TGCGI'AS'ACAACTAA'l"l"'fC'l"lGATAA'l'CAGTTAGCAGTT D G D L I IC L R D I L IC Q G A M P D 1C IC M p G V P I A Y 'l' 'I' II P L 1C D II Q L A V 1200 400 1114 398 AYall(l80) J•o JJo 160 320 154 311 Bpaii(llo) ACCI(Jlo) lcll(lao) Bpaii(Jlo) · 1074 351 lao CTTAAAAACAAC'lCAGAATATA'tCGAAACAAC'l"l'CCAAATCTTATACAGATGGAAAAA'l"l'AATA~A'l"l'CTGGTGG'l"''ATGTAGC:CCAATTCAATATATC:TTGGCATGAACTAAGT V IC II M I I Y I I 'I' 'l' S IC S Y 'I' D G IC I N I D H S G G Y V A Q P N I 8 W D E V S 1 J20 440 .!lo GTTAAAAATAATTCGGAATATATCGAAA::!AACTTCTAAGGCTTACTCGGATGGAAAAA'l"l'AAC:CTAGATCATTCCGG"l'GCCTATGT'l'Gc:GAGATTCAATG'l"l'ACT'I'GGGATGAAGTTAGC V K N M 8 I I I I 'l' T S K A Y I D G K I N L D H 8 G A Y V A R F H V 'I' W D z· V S 1 Jl4 'fAtcAc:c:AGAAO:GAAATGAAATAAAACTTCATAAGAAATGGCGc:GAAAA'l'TATAAGAGTAAGTTAGCTCA'l"l'TCACTTCTTCTATC'l'ATTTGCCAGGAAATGCGAGAAATA'I"l'AACATC I D I M G H I I K V M lC IC W G I H Y K 8 1C L A H r T 8 8 I Y L P G N A R N I H I TATGATGCTAATGGAAATGAAG'I"''G'''''GAACATAAAM.A~TGATAAAGAT AAGTTAQCTCATTTTACGACATCAATC'l'AT'n'GCCAGGGAATGCAAGGAATA'I"l'AATA'I'T Y D A N G N I V V K H K K W 8 I H D I D I L A H T T 8 I Y L p G H A R N I N I 1440 480 TATGCAAGA~'l'i'f~'11GliiiGGGAA~~QMCTCT'l'AtAGA'I'GACAGAAACTTACCAT'I'AGTAAA.AAATACAAA'I'CTATCTATTTGGCGTACAACCCTTTACCCAAGA 15110 520 1554 518 llpall(11o) l•o .i lo Jao r BpaU(lao)•· Y A R l'k- '" "&" 11:- 'C" ) --~ f" lr f ll' 'l' V I D D R N L P L V lC N R H V I I II G T 'l' L Y P R iJO CANCGAAAGAATG'I'ACTGGCTTGGC'i'TGGGAATGG'l'GGAGAACGGTTGTGCATGATAGAAAC'l'TGCCAT'I'AGTAAAAAATAGAAATG'lTl'GTATC'l'GGGGAACAACGC'lTl'ATCCAGCG HA Kl,F_g_'l'_,9_~,!_W_§._W_'!,..RJ T ·V V DDR N L P LV lC N R R V C I N G T '1' L Y PA lao CATTCTAATAATCTACATAATCCGATTCAGTAGTAA 1596 ~ H S N H V D N P I 0 EndEnd 530 ~lo TATA~TACTGTAGATAATCCAATTAAGTAA Y S D T V D II P l 1t End 438 1434 478 1581 528 Fis. I. Nucleotide and deduced amino acid sequences of lso (34.6% G+C) and ilo (35.5% G+C). A few restriction sites, setving as landmarks, are indic:ated above the DNA sequence. The presumptive signal peptide is underlined, the conserved undecapetide is boxed with a broken line. Phe-489 in LSO and Cys-509 in ILO are indicated by arrows. 83 Ala) at position 489. Ala-489 is the sixth amino acid residue in the undecapeptide believed to be absolutely conserved among all thiol-activated cytolysins sequenced so far [7,9,17,18], irtcluding LLO from L. monocytogenes [4,13]. By site-directed mutagenesis it has been demonstrated by others that the integrity of t.I)J~. gQ.m.ain, and in particular the presence of certain trypt(>,'ph~öe residues, is crucial for the hemolytic activity of these toxins [1]; this is also true for LLO from L. monocytogenes [14]. Although the normally conserved alanine is replaced in LSO by another hydrophobic, nonpolar, uncharged amino acid, the bulky aromatic ring of phenylalanine might have some detrimental effect on the hemolytic activity of LSO, compared to ILO LSO LLO LLO. This notion is supported by the fact that the phenylalanine is directly adjacent to the critical tryptophane residues. To ensure that the observed amino acid substitution in LSO did not result from a cloning artifact during the construction of pAHA9, the relevant chromosomal region of L. seeligeri was amplified by the poJymerase chain reaction (PCR). The DNA sequence determined from the PCR product was identical to the one found for pAHA9. (ii) The conserved undecapeptide mentioned above is termed the 'cysteine motif', as it contains the single cysteine residue in all thiol-activated cytolysins analyzed so far. It has been reported that the presence of this cysteine is not absolutely requircd for the hemolytic activity of pncu- MKKIML~LM%L~VSLP~AQ~A-DAS~(-~IS~~ ILO LSO LLO MK~LVIMSLL VSLP~Q~A00D~S~IS~ M K K IM LV FIT LI LV S L 'PI A QQ TE AI< DAS A F NI<- E N SI S SM -- · - - - - - - - - - - - - - - - - - - - - - - --A • APPASPPArilPK'l'PiVlEKRlHJAJA"OliJl.(Q]YIOGLDYfDlKNJÜilLVYfDJ ~P[i)S PP AllJP K 'l' PbzJE K K H AliJi"I[W'1fY I[i}G L(IDYI!!JK Nl!:.l.JL V Yl.gj A P P A S P P A S: P lC T P I E K K H A.D E I D K Y I Q G L D Y N lC N N V L V Y H ILO LSO LLO GrilA V[!)N V P PfR:iJG Y K(!]G_NI'ölY.I V V E K K K K srf1N Q N NA D I..Q.. vrilN G~AVTNVPP~GYKDG~YIVVEKKKIC~NQNNADIWV~N G .D A V T N V P P R K G Y K D G N E Y I V V E K K K lC S I N Q N N A D I Q V V N ILO mi!) S L T Y P G A LV K A N S E LV E N Q P D V L P V lC R 38 40 39 78 80 79 118 120 119 158 160 LLO D S (2JT L S I D L P AISSLTYPGALVKAN~ELVENQP~VLPVKRDSL'l'LS~DLP AISSLTYPGALVKANSELVENQPDVLPVKRDSLTLSIDLP LSO 159 ILO GM~:~DN00tvVmNATKSH00N~~VHTLV~RWH~KY~YPH 198 LSO LLO GM'l' QDNKIVVKNATKSNVNNAVN'l'LVERWNEKYAQAYPN 199 ILO LSO ~A KID y_Q['Q]E M A Y SES Q L~AK F G(!]A F lC AV N N S LN V N F GA I ~AKIDY~EMAYSESQLIAKFGTAFKAVNNSLNVNF00AI VSAKIDYDDEMAYSESQLIAKFG'l'AFICAVNNSLNVNFGAI 238 SEGK~QEEVI~FKQIYY~NVNEPT~PSRFFG_K~V'l'l<E~L - 278 LW SEGKMQEEVISFKQIYYNVNVNEP'l'RPSRFFGKAVTKEQL 279 ILO ~ALGVNAENPPAYISSVAYGR~VYWKLS~SRS~VlC~AF 320 QALGVNAENPPAYISSVAYGRQVYLKLS'l'NSHSTKVKAAF 319 DAA~GKSV;GDVEL~NII~N~SFRAVIYGGSAKDEV~II 358 LLO ILO LSO LSO LLO ILO GMTKKDNKI~VKN00'l'KSNVNNAVNTLVERWN~lCY~AYPN S~GK~QEEVISFKQIYYNINVNEP'l'~PS~FFG~V'l'KEQL Q AL G V NA E NP PA Y I S SV A Y G RüiJLVt K L S~ S H S ~V lC A A F 200 240 239 280 318 LLO ~AAM GKSVI<GDVELYNIITNSSFKAVIYGGSAK00EV~II TAA SGKSV GDVELTNIIKNSSFRAVIYGGSAKDEVQII IU., DG~L~LRDILK~GA~PGVPIAY'l'TNFLKDN;LAV LSO LLO DGNL~LRDILKTGS~~PGVPI~YTTNFLICDNDLAV 400 DGNLGDLRDILKKGATFNRETPGVPIAYTTNFLKDN LAV 399 ~l<NNSEYIE~'l'SKAYmDGV.IN~DHSG~YVA~FN~WDEV~ 438 LSO ILO LSO LLO ILO LSO LLO ILO LSO LLO ~LO LSO ~l<NNSEYI~'l''l'SK~YTDGRINIDHSGGYVAQFN~WDEVS IlCNNSEYIETTSKAYTDGKINIDHSGGYVAQFNISWDEV YD~GNE~HK~WSEN~l<~KLAHFT00SIYLPGNARNINm YD~GNE~HK~W~EN~KSKLAHFTSSIYLPGNARNINW Y D P E G N E I V Q H K N W S E N N lC S K L A H F T S S I Y L P ~ y [!!JA Kr-E-CT-G-LA_W_E_W'i"i1T vl!]o D RN L P LV K N R NfV':gi y A R:E C T G L[!) W E W W R•T V I D D RN L P LV K N R N lY.fS I Y A K~_C_'l'_q_ !!~.W_J_w_'!,~jT V I D D RN L P LV K N RN I S I Y S ~V D N P I m:J S N N V D N P I lil lQJ G NA R N I NV W G T TL Y Pf'Äl W G T T L Y PL!J WG T T L Y P K 360 359 398 440 439 478 480 479 518 520 519 528 530 LLO YS NKV DNP I E 529 Fig. 2. Comparison of the deduced amino acid sequences for ILO and LSO with the LLO sequence (Refs. 4. 13). Regions in ILO und/tlf LSO which are not identical to LLO are boxed. The presumptive signal peptide is indicated hy a broken line. lhe pnsilinn wh.:re LSO Iacks one positive charge is marked. The additional Ser-33 in LSO is indicatcd by a black dot below the sequence. Phe-489 in LSO and Cys-~119 in ILO by arrows above. 84. molysin; Ul streptolysin 0 [15] and also Iisteriolysin 0 (LLOl from L. monocytogenes [14]. Our results show that lLO contains two cysteine residues, one in the conserved region and another one 26 amino acids distal from there (position 509 in Figs. 1 and 2). Although all members of this group of toxins are oxygentabileFandriJtbl~baetivat~d;·-: only,; IL(),,. migbt be able to f~i.nl,,:·i~tQmöi~~t•r' ··d.i$~l(id~ bonds upon· oxidation. · Furtli,~t· sttidl~s~~itf~::tlie. purlfted~ proteiil and ·with the isolated' lso· and:; ilo g~nes will show the significance of the differences described here to LLO and to the other toxins in this group. We are grateful to W. Goebel for his continuing interest and support and to K. Brehm for discussions and technical advice. M. Leimeister-Wächter and T. Chakraborty are thanked for kindly providing the h/yspecific gene probe, M. Wuenscher for his help in preparing the manuscript. This work was supported by grants from the Bundesministerium für Forschung und Technologie (BMFT 01 Kl 88059) and the Fonds der Chemischen Industrie (to J.K.). A.H. was recipient of a fellowship from the Boehringer lngelheim Fonds. References I Boulnois. O.J.• Mitchell. T.J .• Saunders, F.K.• Mendez. F.J. and Andrew. P.W. (1990) In Bacterial Protein Toxins (Rappouli. R. et al.. eds.). pp. 43-51. Fischer. Stuttgart. 2 Chakraborty, T. and Goebel, W. (1988) Curr. Top. Microbiol. lmmunol. 138, 41-58. 3 Cossart, P. and Mengaud. J. (1989) Mol. Biol. Med. 6, 463-474. 4 Domann, E. and Chakraborty, T. ( 1989) Nucleic Acids Res. 17(15), 6406. S Gaillard, J.L., Berche. P.• Mounier, J., Richard. S. and Sansonetti, P. ( 1987) lnfect. Immun. SS, 2822-2829. 6 Geoffroy, C., Gaillard, J.L.• Alouf, J.E. and Berche, P. (1989) J. Gen. Microbiol. 135,481-487. 7 Geoffroy, C., Mengaud, J., Alouf, J.E. and Cossart, P. (1990) J. Bacteriol. 172, 7301-7305. 8 Hof, H. and Hefner, P. (1988) lnfection 16 (S2), 141-144. 9 Kehoe, M.A., Miller, L., Walker, J.A. and Boulnois, G.J. (1987) lnfect. Immun. 55, 3228-3232. 10 Kreft. J., Funke, D., Haas, A., Lottspeich, F. and Ooebel, W. (1989) FEMS Microbiol. Lett. 57, 197-202. II Leimeister-Wächter, M. and Chakraborty, T. (1989) Jnfect. Immun. 57, 2350-2357. 12 Mead, D.A., S1.czesna-Skorupa, E. and Kemper. 8. (1986) Prot. Eng. 1. 67-74. 13 Mengaud. J.• Vicente, M.F., Chenevert, J., Moniz Pereira, J .• Oeoffroy, C.• Oicquei-Sanzey, B.• Buquero, F.• Perez-Diaz, J.C. and Cossart, P. (1988) lnfect. Immun. 56, 766-772. 14 Michel, E., Reich, K.A .• Favier, R.• Berche, P. and Cossart, P. (1990) Mol. Microbiol. 4, 2167-2178. 15 Pinkney, M., Beachey, E. and Kehoe, M. (1989) lnfect. Immun. 57, 2553-2558. 16 Smyth, C.J. and Dunc:an. J.L. (1978) In Bacterial Toxinsand Cell Membranes (Jeljaszewicz, J. and Wadström, T., eds.). pp. 129183, Academic Press, London. 17 Tweten. R.K. (1988) lnfect. Immun. 56, 3235-3240. 18 Walker, J.A.. Allen, R.L., Falmagne, P., Johnson, M.K. and Boulnois. O.J. ( 1987) lnfect. Immun. 55, 1184-1189.