MMAB adenosylates cob(I)alamin

Stable Identifier
Reaction [transition]
Homo sapiens
2 ATP + 2 cob(II)alamin + reduced (electron-transfer flavoprotein) => 2 adenosylcob(III)alamin + 3 H(+) + oxidized (electron-transfer flavoprotein) + 2 triphosphate
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In a complex reaction, MMAB (mitochondrial cob(I)yrinic acid a,c diamide adenosyltransferase) homotrimer mediates the conversion of cob(II)alamin to a transient cob(I)alamin form which is then adenosylated to form adenosylcobalamin (AdoCbl) (Banerjee et al. 2021; Campanello et al. 2018; Fan & Bobik 2008, Leal et al. 2003; Stich et al. 2005). Defects in MMAB cause methylmalonic aciduria type cblB (MMAB aka methylmalonic aciduria type B or vitamin B12 responsive methylmalonicaciduria of cblB complementation type; MIM:251110). Affected individuals have potentially life-threatening methylmalonic aciduria and metabolic ketoacidosis, despite a functional methylmalonyl CoA mutase (Dobson et al. 2002).
Literature References
PubMed ID Title Journal Year
33797888 Redox-Linked Coordination Chemistry Directs Vitamin B12 Trafficking

Gouda, H, Pillay, S, Banerjee, R

Acc Chem Res 2021
12438653 Identification of the gene responsible for the cblA complementation group of vitamin B12-responsive methylmalonic acidemia based on analysis of prokaryotic gene arrangements

Dobson, CM, Hudson, T, Doré, C, Gravel, RA, Rosenblatt, DS, Wu, X, Leclerc, D, Wai, T, Wilson, A

Proc. Natl. Acad. Sci. U.S.A. 2002
18251506 Functional characterization and mutation analysis of human ATP:Cob(I)alamin adenosyltransferase

Bobik, TA, Fan, C

Biochemistry 2008
30282455 Sacrificial Cobalt-Carbon Bond Homolysis in Coenzyme B12 as a Cofactor Conservation Strategy

Gouda, H, Killian, MM, Rosenblatt, DS, Gupta, A, Banerjee, R, Watkins, D, Smith, JL, Ruetz, M, Brunold, TC, Twahir, UT, Campanello, GC, Dodge, GJ, Warncke, K

J Am Chem Soc 2018
15913339 Spectroscopic evidence for the formation of a four-coordinate Co2+ cobalamin species upon binding to the human ATP:cobalamin adenosyltransferase

Stich, TA, Brunold, TC, Banerjee, R, Yamanishi, M

J Am Chem Soc 2005
12514191 Identification of the human and bovine ATP:Cob(I)alamin adenosyltransferase cDNAs based on complementation of a bacterial mutant

Bobik, TA, Kima, PE, Park, SD, Leal, NA

J. Biol. Chem. 2003
Catalyst Activity

transferase activity, transferring alkyl or aryl (other than methyl) groups of 3xMMAB [mitochondrial matrix]

Orthologous Events
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