>TIGR02317 prpB methylisocitrate lyase; InterPro: IPR012695 Propionate is the second most abundant low molecular mass carbon source found in soil, being generated by the degradation of several amino acids, fementation of crabohydrates and the oxidation of odd-chain fatty acids. Many different organisms are capable of metabolising propionate and several distinct pathways for utilising this compound exist, all of which begin with its activation to propionyl-CoA . Many bacteria metabolise propionate to pyruvate by the 2-methylcitric acid cycle. In the first step, catalysed by methycitrate synthase, oxaloacetate and propionyl-CoA are condensed to form 2-methylcitrate and CoA. The 2-methylcitrate is subsequently converted to 2-methylisocitrate by the combined actions of a dehydratase and an aconitase. In the final step, 2-methylisocitrate lyase cleaves a C-C bond within this compound to form succinate and pyruvate. The succinate is further oxidised to oxaloacetate which re-enters the cycle, while the pyruvate can be used further for either energy generation or biomass synthesis. Proteins in this entry are mostly 2-methylisocitrate lyases. Some of them have been annotated (incorrectly it seems) as the related protein carboxyphosphoenolpyruvate phosphomutase, which is involved in synthesizing the antibiotic bialaphos in Streptomyces hygroscopicus. Structural studies indicate that these enzymes belong to the isocitrate lyase family, binding a Mg(2+) cofactor and forming a TIM barrel fold , . As with other enzymes in this family, substrate-binding induces a conformational change that prevents solvent access to the active site and which is important for catalysis. .

Probab=92.87  E-value=0.41  Score=24.90  Aligned_cols=12  Identities=8%  Similarity=0.158  Sum_probs=6.4

Q ss_pred             HHHHHHCCCCEE
Q ss_conf             999997699799
Q gi|254781020|r  200 IELGLKSGIRYF  211 (337)
Q Consensus       200 ~~~a~~aGad~i  211 (337)
T Consensus       168 A~aYvEAGAD~I  179 (287)
T TIGR02317       168 AKAYVEAGADMI  179 (287)
T ss_pred             HHHHHHHCCCCC
T ss_conf             986787261531