Document Detail

Radical SAM-dependent carbon insertion into the nitrogenase M-cluster.
MedLine Citation:
PMID:  23019652     Owner:  NLM     Status:  MEDLINE    
The active site of nitrogenase, the M-cluster, is a metal-sulfur cluster containing a carbide at its core. Using radiolabeling experiments, we show that this carbide originates from the methyl group of S-adenosylmethionine (SAM) and that it is inserted into the M-cluster by the assembly protein NifB. Our SAM cleavage and deuterium substitution analyses suggest a similarity between the mechanism of carbon insertion by NifB and the proposed mechanism of RNA methylation by the radical SAM enzymes RlmN and Cfr, which involves methyl transfer from one SAM equivalent, followed by hydrogen atom abstraction from the methyl group by a 5'-deoxyadenosyl radical generated from a second SAM equivalent. This work is an initial step toward unraveling the importance of the interstitial carbide and providing insights into the nitrogenase mechanism.
Jared A Wiig; Yilin Hu; Chi Chung Lee; Markus W Ribbe
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Science (New York, N.Y.)     Volume:  337     ISSN:  1095-9203     ISO Abbreviation:  Science     Publication Date:  2012 Sep 
Date Detail:
Created Date:  2012-09-28     Completed Date:  2012-10-02     Revised Date:  2013-12-04    
Medline Journal Info:
Nlm Unique ID:  0404511     Medline TA:  Science     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1672-5     Citation Subset:  IM    
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MeSH Terms
Bacterial Proteins / chemistry*
Carbon / chemistry*
Catalytic Domain
Deuterium Exchange Measurement
Methyltransferases / chemistry
Nitrogenase / chemistry*
RNA / chemistry*
S-Adenosylmethionine / chemistry*
Grant Support
Reg. No./Substance:
0/Bacterial Proteins; 0/NifB protein, Bacteria; 63231-63-0/RNA; 7440-44-0/Carbon; 7LP2MPO46S/S-Adenosylmethionine; EC; EC 2.1.1.-/Methyltransferases
Comment In:
Science. 2012 Sep 28;337(6102):1617-8   [PMID:  23019640 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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