>TIGR01893 aa-his-dipept aminoacyl-histidine dipeptidase; InterPro: IPR001160 Metalloproteases are the most diverse of the four main types of protease, with more than 50 families identified to date. In these enzymes, a divalent cation, usually zinc, activates the water molecule. The metal ion is held in place by amino acid ligands, usually three in number. The known metal ligands are His, Glu, Asp or Lys and at least one other residue is required for catalysis, which may play an electrophillic role. Of the known metalloproteases, around half contain an HEXXH motif, which has been shown in crystallographic studies to form part of the metal-binding site . The HEXXH motif is relatively common, but can be more stringently defined for metalloproteases as 'abXHEbbHbc', where 'a' is most often valine or threonine and forms part of the S1' subsite in thermolysin and neprilysin, 'b' is an uncharged residue, and 'c' a hydrophobic residue. Proline is never found in this site, possibly because it would break the helical structure adopted by this motif in metalloproteases . Peptidases are grouped into clans and families. Clans are groups of families for which there is evidence of common ancestry. Each clan is identified with two letters, the first representing the catalytic type of the families included in the clan (with the letter 'P' being used for a clan containing families of more than one of the catalytic types serine, threonine and cysteine). Some families cannot yet be assigned to clans, and when a formal assignment is required, such a family is described as belonging to clan A-, C-, M-, S-, T- or U-, according to the catalytic type. Some clans are divided into subclans because there is evidence of a very ancient divergence within the clan, for example MA(E), the gluzincins, and MA(M), the metzincins. Families are grouped by their catalytic type, the first character representing the catalytic type: A, aspartic; C, cysteine; G, glutamic acid; M, metallo; S, serine; T, threonine; and U, unknown. The serine, threonine and cysteine peptidases utilise the amino acid as a nucleophile and form an acyl intermediate - these peptidases can also readily act as transferases. In the case of aspartic, glutamic and metallopeptidases, the nucleophile is an activated water molecule. This majority of this group of proteins are aminoacyl-histidine dipeptidases (3.4.13.3 from EC, Xaa-His dipeptidases), which are zinc-containing metallopeptidases that belong to MEROPS peptidase family M20 (clan MH), subfamily M20C . Proteins of this clan have two catalytic zinc ions at the active site, bound by His/Asp, Asp, Glu, Asp/Glu and His , . The catalysed reaction involves the release of an N-terminal amino acid, usually neutral or hydrophobic, from a polypeptide.. The X-His dipeptidases cleave Xaa-His dipeptides (where Xaa is any hydrophobic residue). The amino acid sequence deduced from Escherichia coli reveals that peptidase D is a slightly hydrophilic protein of 485 residues that contains no extended domains of marked hydrophobicity . Also contained within this family of proteins are acetylornithine deactylases which belong to MEROPS peptidase family M20, subfamily M20A non-peptidase homologues. ; GO: 0008769 X-His dipeptidase activity, 0006508 proteolysis.

Probab=100.00 E-value=5.9e-43 Score=282.81 Aligned_cols=362 Identities=21% Similarity=0.250 Sum_probs=262.9 Q ss_pred CCHH-HHHHHHHHHCCCCCCCCHHHHHHHHHHHHHHCCCEEEEEEECCCCCCEEEEEEEEEC-CCCCEEEEECCCCCCCC Q ss_conf 9878-999999996499978996899999999999779848999705888762489999987-99988999733681578 Q gi|254780782|r 1 MTPD-CLEHLIQLIKCPSVTPQDGGAFFILVNTLKLLGFSIEEKDFQTKNTSIVKNLYARFG-TEAPHLMFAGHIDVVPP 78 (389) Q Consensus 1 l~~e-~v~~l~~lv~ips~s~~e~~~~~~l~~~l~~~G~~~~~~~~~~~~~~~~~~~~~~~g-~~~~~ill~~H~Dtvp~ 78 (389) T Consensus 1 L~~~~V~~~F~EiskIPR~S~nek~~~~F~~~~AK~lgle~~~D~----~~Nv~IrkPAT~GyEn~p~ivLQ~H~DMVCE 76 (506) T TIGR01893 1 LKPSRVLKYFEEISKIPRPSKNEKEVSNFIVNWAKKLGLEVKQDE----VGNVLIRKPATPGYENKPGIVLQGHMDMVCE 76 (506) T ss_pred CCCHHHHHHHHHHHCCCCCCCCHHHHHHHHHHHHHHCCCEEEEEE----ECCEEEEECCCCCCCCCCCEEEECCCCCCCC T ss_conf 960157787888731789884277899999984442187478743----1558898077537888787488124377354 Q ss_pred CCHH---HCCCCCCCEEEECCCCCCCC-C---CCCCCHHHHHHHHCCCCCCCCCCCCCEEEEEEEECCCEECCCCCCCCC Q ss_conf 8877---72566642245213323654-4---333201245441000000011357834999752022011044211111 Q gi|254780782|r 79 GDFN---HWTYPPFSATIAEGKIYGRG-I---VDMKGSIACFIAAVARFIPKYKNFGSISLLITGDEEGPAINGTKKMLS 151 (389) Q Consensus 79 ~~~~---~W~~~Pf~~~~~~g~l~GrG-~---~D~Kg~ia~~l~a~~~l~~~~~~~~~i~~~~~~dEE~~~~~G~~~l~~ 151 (389) T Consensus 77 K~~d~~HDF~KDPI~~~~dG~~l~A~grTTLGADNGIgVA~~lA~le~~ik~~l~HPplElL~T~~EE~gm-~GA~gL~~ 155 (506) T TIGR01893 77 KNEDSEHDFEKDPIELIVDGDWLKARGRTTLGADNGIGVAMGLAILEDAIKNNLKHPPLELLFTVDEETGM-DGALGLEE 155 (506) T ss_pred CCCCCCCCCCCCCEEEEECCCEEECCCEEECCCCCHHHHHHHHHHHHHHHHCCCCCCCEEEEEEECCCCCC-HHHHHCCC T ss_conf 57877888745861089828578727605504550799999999998853025787864588860000452-23321255 Q ss_pred CCCCCCCC--CC-----EEEEC-CCCCCCCC-----CEEEEEE-EEEEEEEEEEEEE-ECCCCHH-HHCCC-CHHHHHHH Q ss_conf 00013321--20-----35414-56654343-----1001232-2235799999964-1231000-00012-01345544 Q gi|254780782|r 152 WIEKKGEK--WD-----ACIVG-EPTCNHII-----GDTIKIG-RRGSLSGEITIHG-KQGHVAY-PHLTE-NPIRGLIP 214 (389) Q Consensus 152 ~~~~~~~~--~d-----~~i~~-ep~~~~~~-----~~~i~~g-~rG~~~~~i~v~G-~~~Hs~~-p~~g~-nAi~~~~~ 214 (389) T Consensus 156 ~~~~G~~LiNiDsEeeG~~~vGCAGG~~~~~~lp~~~e~~~~~~GsG~~~~~I~~~GL~GGHSG~dIH~~RANankLm~~ 235 (506) T TIGR01893 156 NLLEGKILINIDSEEEGELLVGCAGGINVEITLPVKYEKFEKDEGSGFKGYRISLKGLKGGHSGADIHKGRANANKLMAR 235 (506) T ss_pred CCCCCCEEEECCCEEEEEEEEEECCCEEEEEEECCCEEEEECCCCCCEEEEEEEEECCCCCCCCCHHCCCHHHHHHHHHH T ss_conf 50016501213753334899972276046788255002323366641247999965376687554011122358999999 Q ss_pred HHHCCCCCCCCCCCCCCCCEEEEEEEEEECCCCCCCCCCC---------------------------------------- Q ss_conf 3201122334456644210146676554204666554321---------------------------------------- Q gi|254780782|r 215 LLHQLTNIGFDTGNTTFSPTNMEITTIDVGNPSKNVIPAQ---------------------------------------- 254 (389) Q Consensus 215 ~i~~l~~~~~~~~~~~~~~~~~~i~~i~~g~~~~NvIP~~---------------------------------------- 254 (389) T Consensus 236 ~L~~~~~n~-~k-------e~~~L~~i~-GGS~~NAIPrEA~a~ia~~~~d~~~~~~~v~~~~~~~K~~Y~~~~~~~~~~ 306 (506) T TIGR01893 236 VLSELKENL-DK-------ENFRLSDIK-GGSKRNAIPREAKALIAIDEEDVKKLEELVKNFQSKFKKEYSELEPNITLE 306 (506) T ss_pred HHHHHHHCC-CC-------CCEEEEEEE-CCCCCCCCCCCEEEEEEECCCHHHHHHHHHHHHHHHHHHHHHHCCCCCEEE T ss_conf 999998337-92-------405787741-787256774414799998152089999998889998766653118883189 Q ss_pred -------------------------------------------------------------------------EEEEECC Q ss_conf -------------------------------------------------------------------------1665134 Q gi|254780782|r 255 -------------------------------------------------------------------------VKMSFNI 261 (389) Q Consensus 255 -------------------------------------------------------------------------a~~~~di 261 (389) T Consensus 307 ~~~~E~~iifeasGGkitrkev~~~~v~s~~~~~k~i~~~~~~p~GV~~~~~~~~~~VeSS~NL~~~~~~~~~~~~~~~~ 386 (506) T TIGR01893 307 VSKEENSIIFEASGGKITRKEVKSEKVFSEETTEKLINALNLLPNGVQRVSDELPGLVESSLNLAVVKTKENKVIVVFLI 386 (506) T ss_pred EEEECCEEEEECCCCEEEEECCCCCCCCCHHHHHHHHHHHHHCCCCCCHHHHCCCCEEEEECCEEEEEEECCEEEEEEEE T ss_conf 98632617884378723310047654474257899999997358983105530598266304438899847679999887 Q ss_pred CCCCHHHHHHHHHHHHHHHHHHHHHHCCCCEEEEECCCCCCCCCCCHHHHHHHHHHHHHHHHCCCCEEEECCCCCHHHHH Q ss_conf 34206779999999999876532420343112322266311257867899999999999982899579741454358898 Q gi|254780782|r 262 RFNDLWNEKTLKEEIRSRLIKGIQNVPKLSHTVHFSSPVSPVFLTHDRKLTSLLSKSIYNTTGNIPLLSTSGGTSDARFI 341 (389) Q Consensus 262 R~~~~~~~~~i~~~i~~~l~~~~~~~~~~~~~i~~~~~~~p~~~~~~~~l~~~l~~a~~~~~g~~~~~~~~gg~~d~~~~ 341 (389) T Consensus 387 RSs~~~~k~~v~~~i~~~~~-----l~--GA~~e~~~~YP~W~p~~~S~ll~~~~kvY~e~~ge~~~v~viHAGLECG~i 459 (506) T TIGR01893 387 RSSVESDKDYVTEKIESIAK-----LA--GAEVEVSAGYPSWQPDPDSNLLDVARKVYKEMFGEDPEVKVIHAGLECGII 459 (506) T ss_pred ECCCCCHHHHHHHHHHHHHH-----HH--CCEEEEECCCCCCCCCCCCCHHHHHHHHHHHHHCCCCEEEEEECCHHHCCC T ss_conf 42561107899889989998-----72--974999838887661677618899999875540789579999664110400 Q ss_pred HHCC-C---EEEEEECCCCCCCCCCEEEHHHHHHHHHHHHHHHHHH Q ss_conf 6059-8---9999004787368784047999999999999999987 Q gi|254780782|r 342 KDYC-P---VIEFGLVGRTMHALNENASLQDLEDLTCIYENFLQNW 383 (389) Q Consensus 342 ~~~i-P---~v~fGp~~~~~H~pdE~i~i~~l~~~~~~~~~~i~~~ 383 (389) T Consensus 460 ~~~~q~~~dmIS~GP~i~d~HsP~ERv~I~Sv~~vw~fL~~~L~~~ 505 (506) T TIGR01893 460 SEKIQPDIDMISIGPNIYDPHSPNERVEISSVEKVWDFLVKVLERL 505 (506) T ss_pred HHCCCCCCCEEEECCCCCCCCCCCCCEEECHHHHHHHHHHHHHHHC T ss_conf 0015898414781760268988865055222134568999998625

HHsearch alignment for GI: 254780782 and conserved domain: TIGR01893