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Anaerobic 5-Hydroxybenzimidazole Formation from Aminoimidazole Ribotide: An Unanticipated Intersection of Thiamin and Vitamin B?? Biosynthesis.

ABSTRACT: Comparative genomics of the bacterial thiamin pyrimidine synthase (thiC) revealed a paralogue of thiC (bzaF) clustered with anaerobic vitamin B12 biosynthetic genes. Here we demonstrate that BzaF is a radical S-adenosylmethionine enzyme that catalyzes the remarkable conversion of aminoimidazole ribotide (AIR) to 5-hydroxybenzimidazole (5-HBI). We identify the origin of key product atoms and propose a reaction mechanism. These studies represent the first step in solving a long-standing problem in anaerobic vitamin B12 assembly and reveal an unanticipated intersection of thiamin and vitamin B12 biosynthesis.

SUBMITTER: Mehta AP

PROVIDER: S-EPMC4753784 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

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Anaerobic 5-Hydroxybenzimidazole Formation from Aminoimidazole Ribotide: An Unanticipated Intersection of Thiamin and Vitamin B₁₂ Biosynthesis.

Mehta Angad P AP Abdelwahed Sameh H SH Fenwick Michael K MK Hazra Amrita B AB Taga Michiko E ME Zhang Yang Y Ealick Steven E SE Begley Tadhg P TP

Journal of the American Chemical Society 20150813 33

Comparative genomics of the bacterial thiamin pyrimidine synthase (thiC) revealed a paralogue of thiC (bzaF) clustered with anaerobic vitamin B12 biosynthetic genes. Here we demonstrate that BzaF is a radical S-adenosylmethionine enzyme that catalyzes the remarkable conversion of aminoimidazole ribotide (AIR) to 5-hydroxybenzimidazole (5-HBI). We identify the origin of key product atoms and propose a reaction mechanism. These studies represent the first step in solving a long-standing problem in ...[more]

PMID: 26237670

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