A glycyl free radical as the precursor in the synthesis of carbon monoxide and cyanide by the [FeFe]-hydrogenase maturase HydG

作者：Nicolet Yvain; Martin Lydie; Tron Cecile; Fontecilla Camps Juan C^*

来源：FEBS LETTERS, 2010, 584(19): 4197-4202.

DOI：10.1016/j.febslet.2010.09.008

• FeFe-hydrogenase
• Maturation
• AdoMet
• Glycyl radical
• CO
• Cyanide

HydG uses tyrosine to synthesize the CN(-)/CO ligands of [FeFe]-hydrogenase active site. We have mutated two of the [4Fe-4S]-cluster cysteine ligands of the HydG C-terminal domain (CTD) to serine. The double mutant can still synthesize CN(-) but not CO. In a mutant lacking the CTD both CN(-) and CO synthesis are abolished. Like in ThiH, the initial steps of CN(-) synthesis are carried out in the TIM-barrel domain of HydG but some component(s) of the CTD are later needed. The mutants indicate that CO synthesis is metal-based and occurs in the CTD. We postulate that CN(-)/CO synthesis is initiated by H(2)N--CH-CO(2)(-) Fragmentation of this radical into H(2)N--CH(2) and CO(2) or H(2)C=NH and CO(2)(-) provides plausible precursors for CN(-)/COsynthesis.

• 出版日期2010-10-8
• 单位中国地震局