>TIGR00191 thrB homoserine kinase; InterPro: IPR000870 Saccharomyces cerevisiae strains containing the erg8-1 mutation are temperature sensitive for growth due to a defect in phosphomevalonate kinase, an enzyme of isoprene and ergosterol biosynthesis. Subcloning and DNA sequencing have defined the functional ERG8 regulon as an 850bp upstream region and an adjacent 1,272bp open reading frame. The deduced ERG8 protein contains 424 residues and shows no similarity to known proteins, except within a putative ATP-binding domain present in many kinases . Enzymes that share the N-terminal Gly/Ser-rich putative ATP-binding region include galactokinase, homoserine kinase, mevalonate kinase and phosphomevalonate kinase. Homoserine kinase is a homodimeric enzyme involved in threonine biosynthesis. Sequence comparison of the yeast enzyme with the corresponding proteins from bacterial sources reveals the presence of several highly conserved regions, the pattern of occurrence of which suggests that the ancestral sequences might have been composed from separate (functional) domains. A block of similar residues, found towards the C-terminus, is also present in many other proteins involved in threonine (or serine) metabolism; this motif may therefore represent the binding site for the hydroxy-amino acids. Limited similarity was detected between a motif conserved among the homoserine kinases and consensus sequences found in other mono- or dinucleotide-binding proteins .; GO: 0004413 homoserine kinase activity, 0005524 ATP binding, 0006566 threonine metabolic process.

Probab=99.94 E-value=5.4e-25 Score=177.31 Aligned_cols=290 Identities=21% Similarity=0.185 Sum_probs=196.6 Q ss_pred EEEECCEEEEEECCCEEECCCEEEEEEECCEEEEEEEE----CCCCE-----EEEEECCCCCCCCCCHHHCCCHH-HHHH Q ss_conf 99971704999743533089428987767728999998----68984-----99995364444656612015089-9999 Q gi|254781017|r 8 ICVSAPGSLVLMGEHGVLHGHAALVFAINKRVILYLTL----RKDRL-----INIDSSLGQYCGSLDLAMFHPSF-SFII 77 (324) Q Consensus 8 i~~~aPGKv~L~GEh~v~~G~~ai~~aI~~~~~~~~~~----~~~~~-----i~i~~~~~~~~~~~~~~~~~~~~-~~i~ 77 (324) T Consensus 1 ~~V~vPAsSANlGp-----GFD~LG~aL~~~~~~~~~~~~~~e~~~~~nnCk~~~~~~g-~~~~~iP~~p~~N~~yq~~~ 74 (359) T TIGR00191 1 FKVKVPASSANLGP-----GFDVLGLALSLYNGLTVTDVVAVESDDTPNNCKFEIEAEG-EDVEKIPTEPDDNLIYQVAK 74 (359) T ss_pred CEEEEECCCCCCCC-----CCCEEECEECCCCCEEEECCCCHHHCCCCCCCEEEEEEEC-CCCCCCCCCCHHHHHHHHHH T ss_conf 96862110057774-----4001201003334405504664111058874126888622-45125889612105688999 Q ss_pred HHHHHHCCC---CCEEEEEECCCCCCCCCCCCCHHHHHHHHHHHHHHCCCCCCCHHHHHHHHHHHHHHCCCCCCH---HH Q ss_conf 999971877---873899982687535488740245665567776404566660145578888776521468875---44 Q gi|254781017|r 78 MAINHIKPS---CGFDLKVISQLDSQLGLGSSAAITVAITAALLTLQYHKEPSPDEILTTAHAIVLKVQGISSGI---DL 151 (324) Q Consensus 78 ~~l~~~~~~---~g~~i~i~s~iP~g~GLGSSaa~~va~~~al~~~~~~~~~~~~~i~~lA~~~E~~~~g~~sG~---D~ 151 (324) T Consensus 75 ~~~~~~g~~~~~~p~k~~~~~~iP~grGLGSSAaaiVaa~~a~ne~~-g~~l~~~~~L~~a~~~E~~~----SGs~HpDN 149 (359) T TIGR00191 75 RFLDQLGKRNFIKPVKLTLEKNIPLGRGLGSSAAAIVAALLAANELA-GLPLSKEELLDLALELEGRI----SGSIHPDN 149 (359) T ss_pred HHHHHHCCCCCCCCEEEEEECCCCCCCCCCHHHHHHHHHHHHHHHHH-CCCCCHHHHHHHHHHHHHHC----CCCCCHHH T ss_conf 99998187778887689985385101366638999999999999983-88989899999999986430----57757134 Q ss_pred HH-HHCCCEEEE-EECCC--EE----------EEEE--------------------------CCCCCCEEECCCCCCHHH Q ss_conf 77-662985899-85275--15----------6730--------------------------477752676584179899 Q gi|254781017|r 152 AA-SIHGGLICY-QMPKY--SI----------EKID--------------------------FIFPIHLIYSGYKTPTAQ 191 (324) Q Consensus 152 ~a-~~~Gg~i~~-~~~~~--~~----------~~~~--------------------------~~~~l~l~~tg~~~~T~~ 191 (324) T Consensus 150 vaPa~~GG~~~~~~~~~~Pqeverrei~~~~~~~~P~~GedtGlvPPlPPtdiGrhvkyqWn~~~~~v~aIP~~~~sT~~ 229 (359) T TIGR00191 150 VAPALLGGFQLAVKEDDKPQEVERREIVLLEVLKIPIFGEDTGLVPPLPPTDIGRHVKYQWNSKLKVVLAIPNIEVSTAE 229 (359) T ss_pred HHHHHHCCEEEEEEECCCCCCHHHHHHHHHHHHCCCCCCCCCCCCCCCCCCCCCCCCEEEECCCCCEEEECCCCCCCHHH T ss_conf 67885166279884279876113566656664148898766656797785223442002016765179981784205688 Q ss_pred HHHHHHHHHHHCCCHHHHHHHHHHHHCCCCHHHHHHHCCCC-HHHHHHHHHH--HHHHHH-HHCCCCHHHHHHHH---HH Q ss_conf 99888998860823489999999840332078898730486-4456899999--899998-61678779999999---99 Q gi|254781017|r 192 VLKKISYIEIEYPEINEINQKIYALMGKLSQISCQALRNKN-LKVLAQAMNR--QQGLLE-TLGVSDSKLSEIVW---KL 264 (324) Q Consensus 192 ~v~~v~~~~~~~~~~~~~~~~~~~~~~~i~~~~~~al~~~d-~~~l~~lm~~--~~~~L~-~lgvs~~~l~~li~---~~ 264 (324) T Consensus 230 AR~v---LPk~Y~~~d~v~n-----~~-~l~~l~~A~~~~dP~~~l~~~~~kD~~hqPyR~~L---~P~l~~i-~sCv~~ 296 (359) T TIGR00191 230 ARAV---LPKAYPRQDLVFN-----LS-HLAGLVHALYQKDPKPDLLAIMMKDRIHQPYRESL---IPNLFKI-KSCVQA 296 (359) T ss_pred HHHH---CCCCCCHHHHHHH-----HH-HHHHHHHHHCCCCCHHHHHHHHHCCCCCCCCCCCC---CCHHHHH-HHHHHH T ss_conf 9620---5554678899998-----87-78777756107996289999973385011634223---6148998-999999 Q ss_pred HHCCCCEEEECCCCCCCCEEEEEECCCC-CHHHHHHHHHHHHHCCCEE---EEEECCCCCCCC Q ss_conf 9719945997268997548999846653-2689999999999779789---994145456445 Q gi|254781017|r 265 REQPHIMASKISGSGLGDCVIALGKGDL-NSLPYQSVNCHMHAKGIDI---VPITPSHSTSLY 323 (324) Q Consensus 265 ~~~~g~~~aklsGAG~GG~~i~l~~~~~-~~~~~~~~~~~~~~~g~~~---~~~~~~~~~~~~ 323 (324) T Consensus 297 ~~~~Ga~~~~iSGsGP--Tila~~~e~~G~~~~~~~~~~~~~~~~~e~~v~~~~~d~~G~~~~ 357 (359) T TIGR00191 297 ALEKGALGITISGSGP--TILALADEEFGTEQKAQDLLENLHKQGIEGTVHVLEIDTDGARVE 357 (359) T ss_pred HHHCCCEEEEECCCCH--HHHHCCCCCCCHHHHHHHHHHHHHHCCCCCEEEEECCCCCCCEEE T ss_conf 9735864887112010--555168888775777699987776416532444202335761465

HHsearch alignment for GI: 254781017 and conserved domain: TIGR00191