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Characterization of the enzyme CbiH60 involved in anaerobic ring contraction of the cobalamin (vitamin B12) biosynthetic pathway.

Moore, Simon J., Biedendieck, Rebekka, Lawrence, Andrew D., Deery, Evelyne, Howard, Mark J., Rigby, Stephen E. J., Warren, Martin J. (2013) Characterization of the enzyme CbiH60 involved in anaerobic ring contraction of the cobalamin (vitamin B12) biosynthetic pathway. Journal of Biological Chemistry, 288 (1). pp. 297-305. ISSN 0021-9258. (doi:10.1074/jbc.M112.422535) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:34206)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL
http://dx.doi.org/10.1074/jbc.M112.422535

Abstract

The anaerobic pathway for the biosynthesis of cobalamin (vitamin B(12)) has remained poorly characterized because of the sensitivity of the pathway intermediates to oxygen and the low activity of enzymes. One of the major bottlenecks in the anaerobic pathway is the ring contraction step, which has not been observed previously with a purified enzyme system. The Gram-positive aerobic bacterium Bacillus megaterium has a complete anaerobic pathway that contains an unusual ring contraction enzyme, CbiH(60), that harbors a C-terminal extension with sequence similarity to the nitrite/sulfite reductase family. To improve solubility, the enzyme was homologously produced in the host B. megaterium DSM319. CbiH(60) was characterized by electron paramagnetic resonance and shown to contain a [4Fe-4S] center. Assays with purified recombinant CbiH(60) demonstrate that the enzyme converts both cobalt-precorrin-3 and cobalt factor III into the ring-contracted product cobalt-precorrin-4 in high yields, with the latter transformation dependent upon DTT and an intact Fe-S center. Furthermore, the ring contraction process was shown not to involve a change in the oxidation state of the central cobalt ion of the macrocycle.

Item Type: Article
DOI/Identification number: 10.1074/jbc.M112.422535
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Lin Riches
Date Deposited: 14 Jun 2013 09:41 UTC
Last Modified: 16 Nov 2021 10:11 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/34206 (The current URI for this page, for reference purposes)
Moore, Simon J.: https://orcid.org/0000-0002-1968-206X
Lawrence, Andrew D.: https://orcid.org/0000-0002-5853-5409
Deery, Evelyne: https://orcid.org/0000-0002-8189-678X
Warren, Martin J.: https://orcid.org/0000-0002-6028-6456
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