High resolution X-ray molecular structure of the nitrile hydratase from Rhodococcus erythropolis AJ270 reveals posttranslational oxidation of two cysteines into sulfinic acids and a novel biocatalytic nitrile hydration mechanism.
The crystal structure of Fe-type nitrile hydratase from Rhodococcus erythropolis AJ270 was determined at 1.3A resolution. The two cysteine residues (alphaCys(112) and alphaCys(114)) equatorially coordinated to the ferric ion were post-translationally modified to cysteine sulfinic acids. A glutamine residue (alphaGln(90)) in the active center gave double conformations. Based on the interactions among the enzyme, substrate and water molecules, a new mechanism of biocatalysis of nitrile hydratase was proposed, in which the water molecule activated by the glutamine residue performed as the nucleophile to attack on the nitrile which was simultaneously interacted by another water molecule coordinated to the ferric ion.
Song
Liya
L
State Key Laboratories of Transducer Technology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
Wang
Mingzhu
M
Shi
Jiaji
J
Xue
Zhiquan
Z
Wang
Mei-Xiang
MX
Qian
Shijun
S
D002384:Catalysis; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism; D006836:Hydro-Lyases / Q000737:chemistry* / Q000378:metabolism; D007501:Iron; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D012240:Rhodococcus / Q000201:enzymology*; D013441:Sulfinic Acids / Q000737:chemistry* / Q000378:metabolism; D014867:Water / Q000737:chemistry / Q000378:metabolism
D009570:Nitriles; D013441:Sulfinic Acids; D014867:Water; D007501:Iron; D006836:Hydro-Lyases; C048831:nitrile hydratase; D003545:Cysteine