Crystal structure of hydrogenase maturating endopeptidase HycI from Escherichia coli.
The maturation of [NiFe]-hydrogenases is a catalyzed process involving the activities of at least seven proteins. The last step consists of the endoproteolytic cleavage of the precursor of the large subunit, after the [NiFe]-metal center has been assembled. The HycI endopeptidase is involved in the C-terminal processing of HycE, the large subunit of hydrogenase 3 from Escherichia coli. Although HycI has been well characterized biochemically, the crystallization of the protein has been quite challenging. Here, we present the crystal structure of HycI at 1.70 A resolution. The crystal structure resembles the recently reported solution structure (NMR) of the same protein and the holo-HyPD structure of the same family, but a significant conformational change is observed at the L5 loop, as compared with the solution structures of HycI and HyPD. In our crystal structure, three specific metal binding sites (Ca1-3) were identified and these metal ions are possibly involved in the C-terminal cleavage of HycE.
Kumarevel
Thirumananseri
T
RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan. tskvel@spring8.or.jp
Tanaka
Tomoyuki
T
Bessho
Yoshitaka
Y
Shinkai
Akeo
A
Yokoyama
Shigeyuki
S
D002118:Calcium / Q000737:chemistry; D018360:Crystallography, X-Ray; D010450:Endopeptidases / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology*; D009532:Nickel / Q000737:chemistry; D011487:Protein Conformation
D009532:Nickel; D010450:Endopeptidases; C100872:HycI protease; D002118:Calcium