1n1p
From Proteopedia
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ATOMIC RESOLUTION STRUCTURE OF CHOLESTEROL OXIDASE @ pH 7.4 (STREPTOMYCES SP. SA-COO)
Overview
The X-ray crystal structure of the flavoenzyme cholesterol oxidase, SCOA, (Streptomyces sp.SA-COO) has been determined to 0.95 A resolution. The, large size (55kDa) and the high-resolution diffraction of this protein, provides a unique opportunity to observe detailed electronic effects, within a protein environment and to obtain a larger sampling for which to, analyze these electronic and structural differences. It is well-known, through spectroscopic methods that peptide carbonyl groups are polarized, in alpha-helices. This electronic characteristic is evident in the, sub-Angstrom electron density of SCOA. Our analysis indicates an increased, tendency for the electron density of the main chain carbonyl groups within, alpha-helices to be polarized toward the oxygen atoms. In contrast, the, carbonyl groups in beta-sheet structures tend to exhibit a greater charge, density between the carbon and oxygen atoms. Interestingly, the electronic, differences observed at the carbonyl groups do not appear to be correlated, to the bond distance of the peptide bond or the peptide planarity. This, study gives important insight into the electronic effects of alpha-helix, dipoles in enzymes and provides experimentally based observations that, have not been previously characterized in protein structure.
About this Structure
1N1P is a Single protein structure of sequence from Streptomyces sp. with MN, FAD and GOL as ligands. Active as Cholesterol oxidase, with EC number 1.1.3.6 Full crystallographic information is available from OCA.
Reference
Atomic resolution density maps reveal secondary structure dependent differences in electronic distribution., Lario PI, Vrielink A, J Am Chem Soc. 2003 Oct 22;125(42):12787-94. PMID:14558826
Page seeded by OCA on Tue Nov 20 21:52:32 2007
