>cd04257 AAK_AK-HSDH AAK_AK-HSDH: Amino Acid Kinase Superfamily (AAK), AK-HSDH; this CD includes the N-terminal catalytic domain of aspartokinase (AK) of the bifunctional enzyme AK - homoserine dehydrogenase (HSDH). These aspartokinases are found in bacteria (E. coli AKI-HSDHI, ThrA and E. coli AKII-HSDHII, MetL) and 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-HSDH is an alanine-act

Probab=98.99 E-value=4.1e-09 Score=71.02 Aligned_cols=110 Identities=25% Similarity=0.345 Sum_probs=81.6 Q ss_pred HHHHHCCCEEEECCC-CCCCCCCEECC---CHHHHHHHHHHHHCHHHHHHHCCCCCEEECCC------CCCCCCCHHHHH Q ss_conf 999977984998574-31787320066---14799999998625113343226763353455------555633888999 Q 537021.9.peg.3 16 DLLIKSGIIPVIAPI-APGYDGATYNI---NADTFAGAIAEKLNVIRLLFLTDVPGVLDKNR------QLISKLSINEAR 85 (142) Q Consensus 16 ~~lL~~g~iPVi~pi-g~~~~G~~~ni---n~D~~a~~lA~~l~A~kli~ltdv~Gv~d~~~------~~i~~i~~~e~~ 85 (142) T Consensus 174 ~~~~~~~~v~Vv~GFig~~~~G~~ttLGRgGSD~TAa~ia~~L~A~~v~IwtDV~Gi~taDPr~v~~a~~i~~lsy~EA~ 253 (294) T cd04257 174 AWFSSNGKVIVVTGFIASNPQGETTTLGRNGSDYSAAILAALLDADQVEIWTDVDGVYSADPRKVKDARLLPSLSYQEAM 253 (294) T ss_pred HHHHCCCCEEEECCCCCCCCCCCEEEECCCCHHHHHHHHHHHCCCCEEEEECCCCCCCCCCCCCCCCCEECCCCCHHHHH T ss_conf 98641797899769525678897513489948899999999729978999428885052799768898671604899999 Q ss_pred HHHHCCCCCCCHHHHHHHHHHHHHCCCCEEEEEECCCCCHHHHHHHCCCCCCCEE Q ss_conf 9962697678678999999999984998899952578768999996799866345 Q 537021.9.peg.3 86 TLIKDGTISGGMIPKIETSIKAIENGVKSVAILDGKKPHSILMEIFTKNGSGTLL 140 (142) Q Consensus 86 ~l~~~~~~~~gm~~Ki~~a~~a~~~Gv~~v~i~~~~~~~~ll~elft~~g~GT~i 140 (142) T Consensus 254 eLa~~Ga--kVlHp--~ti~p~~~~~Ip-i~vrnt----------~~p~~~GT~I 293 (294) T cd04257 254 ELSYFGA--KVLHP--KTIQPVAKKNIP-ILIKNT----------FNPEAPGTLI 293 (294) T ss_pred HHHHCCC--CCCCH--HHHHHHHHCCCC-EEEECC----------CCCCCCCEEE T ss_conf 9996798--31599--999999987993-899389----------9989998151

HHsearch alignment for GI: peg_394 and conserved domain: cd04257