1joa

File:1joa.gif

spinqualitylabelsall models 1joa, resolution 2.8Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

NADH PEROXIDASE WITH CYSTEINE-SULFENIC ACID

OverviewOverview

In order to obtain the crystal structure of the flavoprotein NADH, peroxidase with its native Cys42-sulfenic acid redox center, a strategy, combining reduced exposure of crystals to ambient oxygen and data, collection at -160 degrees C was applied. The structure of the native, enzyme to 2.8 A resolution is described; these results conclusively, establish the existence of the Cys42-sulfenic acid as the functional, non-flavin redox center of the peroxidase and provide the first structure, for any naturally occurring protein-sulfenic acid. The Cys42-sulfenic acid, atoms C alpha-C beta-S gamma-O roughly define a planar arrangement which, is stacked parallel to the si face of the FAD isoalloxazine and positions, the sulfenyl oxygen atom only 3.3 A from FAD-C4A. His10-N epsilon 2, contributes a hydrogen bond to the sulfenic acid oxygen, at a distance of, 3.2 A. Although one oxygen atom (OX1) of the non-native Cys42-sulfonic, acid derivative identified in the earlier wild-type peroxidase structure, was taken to represent the native Cys42-sulfenic acid oxygen [Stehle, T., Ahmed, S. A., Claiborne, A., & Schulz, G. E. (1991) J. Mol. Biol. 221, 1325-1344], this structure shows that the sulfenic acid oxygen does not, occupy this position, nor is it hydrogen-bonded to Cys42-N as was OX1., Comparison of the native Cys42-sulfenic acid structure with that of, two-electron reduced glutathione reductase provides an insight into the, sulfenic acid FAD charge-transfer interaction observed with both wild-type, and His10 mutant peroxidases. A model of the E.NADH intermediate recently, observed in stopped-flow analyses of the enzyme [Crane, E. J., III, Parsonage, D., Poole, L. B., & Claiborne, A. (1995) Biochemistry 34, 14114-14124] has also been generated to assist in analyzing the chemical, mechanism of sulfenic acid reduction.

About this StructureAbout this Structure

1JOA is a Single protein structure of sequence from Enterococcus faecalis with FAD as ligand. Active as NADH peroxidase, with EC number 1.11.1.1 Structure known Active Site: ACT. Full crystallographic information is available from OCA.

ReferenceReference

Structure of the native cysteine-sulfenic acid redox center of enterococcal NADH peroxidase refined at 2.8 A resolution., Yeh JI, Claiborne A, Hol WG, Biochemistry. 1996 Aug 6;35(31):9951-7. PMID:8756456

Page seeded by OCA on Mon Nov 5 16:40:54 2007