>cd04243 AAK_AK-HSDH-like AAK_AK-HSDH-like: Amino Acid Kinase Superfamily (AAK), AK-HSDH-like; this family includes the N-terminal catalytic domain of aspartokinase (AK) of the bifunctional enzyme AK- homoserine dehydrogenase (HSDH). These aspartokinases are found in such bacteria as E. coli (AKI-HSDHI, ThrA and AKII-HSDHII, MetL) and in higher plants (Z. mays AK-HSDH). AK and HSDH are the first and third enzymes in the biosynthetic pathway of the aspartate family of amino acids. AK catalyzes the phosphorylation of Asp to P-aspartyl phosphate. HSDH catalyzes the NADPH-dependent conversion of Asp 3-semialdehyde to homoserine. ThrA and MetL are involved in threonine and methionine biosynthesis, respectively. In E. coli, ThrA is subject to allosteric regulation by the end product L-threonine and the native enzyme is reported to be tetrameric. As with bacteria, plant AK and HSDH are feedback inhibited by pathway end products. Maize AK-HSDH is a Thr-sensitive 180-kD enzyme. Arabidopsis AK-

Probab=100.00 E-value=0 Score=560.60 Aligned_cols=236 Identities=39% Similarity=0.564 Sum_probs=213.2 Q ss_pred EEEEECCCCCCCHHHHHHHHHHHHHHHHCCCCEEEEEECCCCHHHHHHHHHHHHHCC----------------------- Q ss_conf 999608584588899999999999999679988999806873048999999986148----------------------- Q gi|254780873|r 4 IVMKFGGTSVANIDCIRSAALHVKREVDRGQEVAMVVSAMSGETDRLAELCRQVTSI----------------------- 60 (411) Q Consensus 4 iV~KfGGtSv~~~~~i~~v~~~i~~~~~~g~~~ivVvSA~~g~Td~L~~l~~~~~~~----------------------- 60 (411) T Consensus 2 kV~KFGGtSv~~~~~i~~v~~iI~~~--~~~~~vVVVSA~~gvTd~L~~~~~~a~~~~~~~~~~l~~i~~~h~~i~~~L~ 79 (293) T cd04243 2 KVLKFGGTSVASAERIRRVADIIKSR--ASSPVLVVVSALGGVTNRLVALAELAASGDDAQAIVLQEIRERHLDLIKELL 79 (293) T ss_pred EEEEECCCCCCCHHHHHHHHHHHHHC--CCCCEEEEECCCCCCHHHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHHHHHC T ss_conf 89987812369999999999999837--7989599981998868999999998843775789999999999999999852 Q ss_pred -------------------------------CCHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCCCCCCCCCCCCCCCC Q ss_conf -------------------------------9988999999831299999999999843998635673324551213355 Q gi|254780873|r 61 -------------------------------DNARERDVVISTGEQVSSGLMVLALQSLGIQAISLQGWQIPIMTDSLHG 109 (411) Q Consensus 61 -------------------------------~~~~~~d~i~s~GE~~s~~l~a~~l~~~G~~a~~l~~~~~~i~t~~~~~ 109 (411) T Consensus 80 ~~~~~~~~~~~i~~~~~~L~~~l~~~~~~~~~~~~~~d~ils~GE~lSa~l~a~~L~~~Gi~a~~ld~~~~-i~td~~~~ 158 (293) T cd04243 80 SGESAAELLAALDSLLERLKDLLEGIRLLGELSDKTRAEVLSFGELLSSRLMSAYLQEQGLPAAWLDAREL-LLTDDGFL 158 (293) T ss_pred CCHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCEEECHHHH-EECCCCCC T ss_conf 71547999999999999999998765422579889999999889899999999999978998099754784-20268875 Q ss_pred CCCCCCC-CCCCHHHHHH-HCCEEEEECCCCCCCCCCEEEECCCCCCHHHHHHHHHHCHHHHHHHCCHHHHEECCCCCCC Q ss_conf 2000123-6210033431-0680586034333556842443068624289999988473455653461440245842123 Q gi|254780873|r 110 MARICRV-DEKKIVTHLK-KKQVVVITGFQGLSHDNSVTTLGRGGSDTSAVAIAAAIKADRCDIYTDVCGIYTTDPRIEP 187 (411) Q Consensus 110 ~a~~~~~-~~~~l~~~l~-~~~v~v~~Gf~g~~~~g~~ttlgRGGSD~tA~~ia~~l~A~~~~i~tdV~Gi~taDPr~v~ 187 (411) T Consensus 159 ~a~~~~~~s~~~~~~~~~~~~~v~Vv~GFig~~~~G~~ttLGRgGSD~sAaila~~l~A~~v~IwtDV~Gi~taDPr~v~ 238 (293) T cd04243 159 NAVVDLKLSKERLAQLLAEHGKVVVTQGFIASNEDGETTTLGRGGSDYSAALLAALLDAEEVEIWTDVDGVYTADPRKVP 238 (293) T ss_pred CCCCCHHHHHHHHHHHHHCCCCEEEECCCCCCCCCCCEEEECCCHHHHHHHHHHHHCCCCEEEEEECCCCEEECCCCCCC T ss_conf 31007764199999986338959997496612799977872798289999999995699889998378840708998788 Q ss_pred CCCEECCCCHHHHHHHHHCCCCCHHHHHHHHHHHCCCEEEEECCCCCCCCCCCCCCCCC Q ss_conf 44110567999999988403110137887643313852676112377777654354545 Q gi|254780873|r 188 KAHLMKKISFEEMLEMSSLGAKVMQVRSVELAMLYKMCLFVRSSFEDHGQQEQLGTLIC 246 (411) Q Consensus 188 ~a~~i~~lsy~Ea~eLa~~Gakvlhp~~~~~~~~~~ipi~i~ntf~~~~~~~~~GT~I~ 246 (411) T Consensus 239 ~a~~i~~lsy~EA~ELa~~GakVlHp~ti~p~~~~~Ipi~i~nt~~----p~~~GT~Is 293 (293) T cd04243 239 DARLLKELSYDEAMELAYFGAKVLHPRTIQPAIRKNIPIFIKNTFN----PEAPGTLIS 293 (293) T ss_pred CCEECCCCCHHHHHHHHHCCCCCCCHHHHHHHHHCCCCEEEECCCC----CCCCCEEEC T ss_conf 8756481089999999977962059999999998699489937999----899982659

HHsearch alignment for GI: 254780873 and conserved domain: cd04243