>TIGR00492 alr alanine racemase; InterPro: IPR000821 Alanine racemase catalyses the pyridoxal-dependent conversion of L-alanine into D-alanine, a key component of bacterial peptidoglycan . In Escherichia coli and Salmonella typhimurium, there are two alanine racemase isoforms, alr is a biosynthetic form required for cell wall formation; and dadB functions in L-alanine catabolism. By contrast with dadB and alr, both of which are monomeric enzymes, the alanine racemase of Bacillaceae are homodimers. In Pseudomonas putida, a broad-specificity amino acid racemase is structurally and functionally related to alanine racemase. The 3D-structure of the dimeric alanine racemase from Bacillus stearothermophilus has been determined to a resolution of 1.9 A . Each monomer comprises two domains, with an eight-stranded alpha/beta barrel at the N-terminus, and a C-terminal beta-strand domain. In the dimer, the mouth of the alpha/beta barrel of one monomer faces the second domain of the other monomer. The pyridoxal 5'-phosphate (PLP) cofactor lies in and above the barrel mouth and is covalently linked via an aldimine linkage to Lys39. Several other residues are involved in anchoring the PLP, for example, Arg219 forms a hydrogen bond with the pyridine nitrogen of the cofactor, which is assumed to influence electron delocalisation in PLP-alanine intermediates; Arg136 donates a hydrogen bond to the phenolic oxygen of PLP, and may be involved in substrate binding and stabilisation of intermediates; and Tyr265' is postulated to be a 2 proton donor to the carbanion intermediate .; GO: 0008784 alanine racemase activity, 0006522 alanine metabolic process.

Probab=99.13 E-value=8.7e-10 Score=87.15 Aligned_cols=204 Identities=22% Similarity=0.293 Sum_probs=151.5 Q ss_pred CHHHHHHHHHHHHHHHHHHCCCCHHHCEEEEECCC----CCHHHHH-HHHHCCCCCCCCCCCHHHHHHHHCCCCC-CCCC Q ss_conf 98999999999999999981989644189987189----9999999-9997298100012100011110000012-5873 Q gi|254780801|r 2 SLGNKLQVFKQKIENSAILAKRPKDSVSLVAVSKM----VDSKKIR-VALSCGQVIFAENKLQEAKKKWIPLRKE-WDVQ 75 (222) Q Consensus 2 ~i~~nl~~i~~~I~~a~~~~gR~~~~v~LiaVtK~----~~~e~I~-~~~~~G~~~fGENrvQE~~~K~~~l~~~-~~i~ 75 (222) T Consensus 12 ALk~Nl~~~k~~~----------~~~~~~~AVVKANAYGHG~~~~a~~~~~~Gad~lavA~LeEAi~----LR~~G~~~P 77 (383) T TIGR00492 12 ALKHNLSAIKKQI----------GPKSKIMAVVKANAYGHGLIEVAKTLLQAGADYLAVATLEEAIE----LRKAGITAP 77 (383) T ss_pred HHHHHHHHHHHHC----------CCCCEEEEEEECCCCCCCHHHHHHHHHHCCCCEEEECCHHHHHH----HHHCCCCCC T ss_conf 8999999999746----------88756999981484260189999999865896640002467799----885478875 Q ss_pred EEEECCCCCCHHHHHCCCCHHCCCCCCCCHHHHHHHHHHHHC--CCEEEEEEEECCCCCCCCCCCCC-HHHHHHHHHHCC Q ss_conf 023024432001320111000012222200134433333311--43036889700466563465700-012223443104 Q gi|254780801|r 76 LRFIGSLQSNKVSEIVSLFDVIETVSREKTASLLSLEMIKQS--RFLPVYIQVNTGYEIQKSGIMPN-QTKDFVILCRQK 152 (222) Q Consensus 76 wHfIG~LQsNKvk~i~~~~~~Ihsvds~~~a~~L~~~~~~~~--~~~~vliQVN~~~e~~K~G~~p~-el~~l~~~i~~~ 152 (222) T Consensus 78 IL~Lg~~~~~~~~~~~~~~~l~~~v~s~Eql~~~~~~~lk~~sa~~l~vhlK~DTG--M~RLG~~~~f~~~~~~~~~~~~ 155 (383) T TIGR00492 78 ILLLGGFFSAEDLKILAAWDLTTTVHSVEQLKALEEALLKEPSAKRLKVHLKIDTG--MNRLGVKPDFEEALFVQKLRAL 155 (383) T ss_pred EEEEECCCCHHHHHHHHHCCCEEEEECHHHHHHHHHHHHHCCCCCEEEEEEEECCC--CCCCCCCCCHHHHHHHHHHHHC T ss_conf 78850479988999998618638980889999999984104478747899862388--8647888657899999999836 Q ss_pred CCCC-HHHHEECCCCCCCC-----HHHHHHHHHHHHHCC------CCEECCCCCHHHHHHHHHC----CCEEEECHHHCC Q ss_conf 3110-01110115433452-----058999999988758------9472247773489999808----988997113238 Q gi|254780801|r 153 YQLN-VEGLMCIPPAMGNP-----KPHFYLLSEIARECK------LTKLSMGMTRDFELAIASG----ATSVRIGSGIFG 216 (222) Q Consensus 153 ~~L~-i~GLMti~p~~~d~-----~~~F~~l~~l~~~~~------~~~LSmGMS~D~~~Ai~~G----st~vRiGs~iFG 216 (222) T Consensus 156 ~~~~~~~gi~sHfa~AD~~~~~~~~~Q~~~F~~~~~~L~~~~i~~~~~~h~aNSaaiL~~~~~~enr~fd~vRpGIiLYG 235 (383) T TIGR00492 156 SKLLELEGIFSHFATADEPKTTTTKKQIERFLSFLEGLKQQKIELIPFRHIANSAAILSLPEGHENRLFDMVRPGIILYG 235 (383) T ss_pred CCCCCCCCEECCCCCCCCCCHHHHHHHHHHHHHHHHHHHHCCCCCCCHHHHHHHHHHHCCCCCCCCCEEEEEECCHHHHC T ss_conf 45643021121456767722147999999999998513436864763354210178644533566640114421435321 Q ss_pred CCCCC Q ss_conf 99999 Q gi|254780801|r 217 ERPCQ 221 (222) Q Consensus 217 ~R~~~ 221 (222) T Consensus 236 ~~Ps~ 240 (383) T TIGR00492 236 LYPSA 240 (383) T ss_pred CCCCH T ss_conf 47620

HHsearch alignment for GI: 254780801 and conserved domain: TIGR00492