Investigating the origins of B12 biosynthesis in the most ancient roots of the tree of life
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Authors
Petrus, Amanda K.
Swithers, Kristen S.
Bibis, Stergios S.
Celone, Veronica
Jutla, Tripta
Alicea, Edil
Issue Date
2015-03-27
Type
Presentation
Language
en_US
Keywords
Vitamin B12 , Cobalamin , Evolution
Alternative Title
Abstract
Vitamin B12, also known as B12 or cobalamin, is a vital nutrient required across all branches of life, but the ability to synthesize this complex molecule de novo is limited to only a few archaea and bacteria. De novo synthesis begins with glutamate and utilizes over 30 gene products to produce an active cobalamin [1]. Previous studies suggest that of the available bacterial genomes, only half utilizing cobalamin can synthesize it [2]. The other half either take up complete cobalamin from the environment via an ABC transporter, or scavenge incomplete corrinoids (partial cobalamin molecules) as precursors to synthesize active cobalamin [3, 4]. The evolutionary histories and identities of multiple genes within these B12 pathways are unknown, leaving gaping holes in our understanding of the only source of biosynthesis of the vitamin so essential to human survival. Genes of particular interest to this investigator are those responsible for producing reductases that act upon the central cobalt atom of B12. Three reductases with unknown gene identities are located within the B12 biosynthetic pathway and it is the aim of this research to identify those genes responsible.