1N4U

CHOLESTEROL OXIDASE FROM STREPTOMYCES @ pH 4.5 (STREPTOMYCES SP. SA-COO)

Summary for 1N4U

• Entry DOI: 10.2210/pdb1n4u/pdb
• Related: 1B4V 1B8S 1CBO 1CC2 1IJH 1N1P 1N4V 1N4W
• Descriptor: Cholesterol oxidase, PHOSPHATE ION, FLAVIN-N7 PROTONATED-ADENINE DINUCLEOTIDE, ... (6 entities in total)
• Functional Keywords: flavoenzyme, steroid metabolism, oxidoreductase, atomic resolution
• Biological source: Streptomyces sp.
• Cellular location: Secreted: P12676
• Total number of polymer chains: 1
• Total formula weight: 56355.18

Authors

Vrielink, A.,Lario, P.I. (deposition date: 2002-11-01, release date: 2004-04-27, Last modification date: 2024-02-14)

Primary citation

Lyubimov, A.Y.,Lario, P.I.,Moustafa, I.,Vrielink, A.
Atomic resolution crystallography reveals how changes in pH shape the protein microenvironment
Nat.Chem.Biol., 2:259-264, 2006

PubMed Abstract: Hydrogen atoms are a vital component of enzyme structure and function. In recent years, atomic resolution crystallography (>or=1.2 A) has been successfully used to investigate the role of the hydrogen atom in enzymatic catalysis. Here, atomic resolution crystallography was used to study the effect of pH on cholesterol oxidase from Streptomyces sp., a flavoenzyme oxidoreductase. Crystallographic observations of the anionic oxidized flavin cofactor at basic pH are consistent with the UV-visible absorption profile of the enzyme and readily explain the reversible pH-dependent loss of oxidation activity. Furthermore, a hydrogen atom, positioned at an unusually short distance from the main chain carbonyl oxygen of Met122 at high pH, was observed, suggesting a previously unknown mechanism of cofactor stabilization. This study shows how a redox active site responds to changes in the enzyme's environment and how these changes are able to influence the mechanism of enzymatic catalysis.

PubMed: 16604066
DOI: 10.1038/nchembio784

Experimental method

X-RAY DIFFRACTION (0.95 Å)