HHsearch alignment for GI: 254780821 and conserved domain: TIGR02082

>TIGR02082 metH methionine synthase; InterPro: IPR011822 Vitamin B12 dependent methionine synthase 2.1.1.13 from EC (5-methyltetrahydrofolate--homocysteine S-methyltransferase) catalyses the conversion of 5-methyltetrahydrofolate and L-homocysteine to tetrahydrofolate and L-methionine as the final step in de novo methionine biosynthesis. The enzyme requires methylcobalamin as a cofactor. In humans, defects in this enzyme are the cause of autosomal recessive inherited methylcobalamin deficiency (CBLG), which causes mental retardation, macrocytic anemia and homocystinuria. Mild deficiencies in activity may result in mild hyperhomocysteinemia, and mutations in the enzyme may be involved in tumorigenesis. Vitamin B12 dependent methionine synthase is found in prokaryotes and eukaryotes, but in prokaryotes the cofactor is cobalamin. This enzyme is a large protein composed of four structurally and functionally distinct modules: the first two modules bind homocysteine and tetrahydrofolate , the third module binds the B12 cofactor , and the C-terminal module (activation domain) binds S-adenosylmethionine. The activation domain is essential for the reductive activation of the enzyme. During the catalytic cycle, the highly reactive cob(I)alamin intermediate can be oxidised to produce an inactive cob(II)alamin enzyme; the enzyme is then reactivated via reductive methylation by the activation domain . The activation domain adopts an unusual alpha/beta fold.Recent studies suggest that this enzyme exists as an ensemble of conformations with equilibria dependent on the oxidation and methylation state of the cobalamin and on the concentrations of substrates or products .; GO: 0008705 methionine synthase activity, 0031419 cobalamin binding, 0050897 cobalt ion binding, 0009086 methionine biosynthetic process.
Probab=93.74  E-value=0.029  Score=33.11  Aligned_cols=28  Identities=21%  Similarity=0.169  Sum_probs=13.9

Q ss_pred             HHHHHHHHHHHHHCCHHHHCCCCCCCCC
Q ss_conf             1469999875320000110011222233
Q gi|254780821|r  245 AATAICAVQMAGFTLEKECINAALQSVQ  272 (429)
Q Consensus       245 a~~Aiaa~~~lg~~i~~~~I~~gL~~~~  272 (429)
T Consensus       536 a~~fI~A~r~IK~~LP~a~isgGvSNvS  563 (1265)
T TIGR02082       536 AIDFIEAIRWIKEELPDAKISGGVSNVS  563 (1265)
T ss_pred             HHHHHHHHHHHHHHCCCCEEECCEEEEE
T ss_conf             7899999999996589728853402221