2DD5

Thiocyanate hydrolase (SCNase) from Thiobacillus thioparus native holo-enzyme

Summary for 2DD5

• Entry DOI: 10.2210/pdb2dd5/pdb
• Related: 2DD4
• Descriptor: Thiocyanate hydrolase alpha subunit, Thiocyanate hydrolase beta subunit, Thiocyanate hydrolase gamma subunit, ... (6 entities in total)
• Functional Keywords: hydrolase, cobalt, metalloprotein, sulfenic acid, sulfinic acid, nitrile hydratase, thiocyanate, carbonyl sulfide, claw setting, protein, enzyme, complex, model complex, non-corrin
• Biological source: Thiobacillus thioparus; More
• Total number of polymer chains: 12
• Total formula weight: 242157.01

Authors

Arakawa, T.,Kawano, Y.,Kataoka, S.,Katayama, Y.,Kamiya, N.,Yohda, M.,Odaka, M. (deposition date: 2006-01-19, release date: 2007-01-30, Last modification date: 2024-10-30)

Primary citation

Arakawa, T.,Kawano, Y.,Kataoka, S.,Katayama, Y.,Kamiya, N.,Yohda, M.,Odaka, M.
Structure of thiocyanate hydrolase: a new nitrile hydratase family protein with a novel five-coordinate cobalt(III) center.
J.Mol.Biol., 366:1497-1509, 2007

PubMed Abstract: Thiocyanate hydrolase (SCNase) of Thiobacillus thioparus THI115 is a cobalt(III)-containing enzyme catalyzing the degradation of thiocyanate to carbonyl sulfide and ammonia. We determined the crystal structures of the apo- and native SCNases at a resolution of 2.0 A. SCNases in both forms had a conserved hetero-dodecameric structure, (alphabetagamma)(4). Four alphabetagamma hetero-trimers were structurally equivalent. One alphabetagamma hetero-trimer was composed of the core domain and the betaN domain, which was located at the center of the molecule and linked the hetero-trimers with novel quaternary interfaces. In both the apo- and native SCNases, the core domain was structurally conserved between those of iron and cobalt-types of nitrile hydratase (NHase). Native SCNase possessed the post-translationally modified cysteine ligands, gammaCys131-SO(2)H and gammaCys133-SOH like NHases. However, the low-spin cobalt(III) was found to be in the distorted square-pyramidal geometry, which had not been reported before in any protein. The size as well as the electrostatic properties of the substrate-binding pocket was totally different from NHases with respect to the charge distribution and the substrate accessibility, which rationally explains the differences in the substrate preference between SCNase and NHase.

PubMed: 17222425
DOI: 10.1016/j.jmb.2006.12.011

Experimental method

X-RAY DIFFRACTION (2 Å)