The X-ray structure of a cobalamin biosynthetic enzyme, cobalt-precorrin-4 methyltransferase.
Biosynthesis of the corrin ring of vitamin B12 requires the action of six S-adenosyl-L-methionine (AdoMet) dependent transmethylases, closely related in sequence. The first X-ray structure of one of these, cobalt-precorrin-4 transmethylase, CbiF, from Bacillus megaterium has been determined to a resolution of 2.4 A. CbiF contains two alphabeta domains forming a trough in which S-adenosyl-L-homocysteine (AdoHcy) binds. The location of AdoHcy and a number of conserved residues, helps define the precorrin binding site. A second crystal form determined at 3.1 A resolution highlights the flexibility of two loops around this site. CbiF employs a unique mode of AdoHcy binding and represents a new class of transmethylase.
Department of Chemistry, University of York, Heslington, UK.
H L
HL
Schubert
K S
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Wilson
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Raux
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Woodcock
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Warren
D000595:Amino Acid Sequence; D001410:Bacillus megaterium / Q000201:enzymology*; D001665:Binding Sites; D002384:Catalysis; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D008780:Methyltransferases / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D012435:S-Adenosylhomocysteine / Q000737:chemistry; D016415:Sequence Alignment; D014805:Vitamin B 12 / Q000096:biosynthesis*
D012435:S-Adenosylhomocysteine; D008780:Methyltransferases; C078454:precorrin-3 11-methyltransferase; D014805:Vitamin B 12