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Protein dynamics and electrostatics in the function of p-hydroxybenzoate hydroxylase.
Arch Biochem Biophys. 2005 Jan 01; 433(1):297-311.AB

Abstract

para-Hydroxybenzoate hydroxylase is a flavoprotein monooxygenase that catalyzes a reaction in two parts: reduction of the enzyme cofactor, FAD, by NADPH in response to binding p-hydroxybenzoate to the enzyme, then oxidation of reduced FAD by oxygen to form a hydroperoxide, which oxygenates p-hydroxybenzoate to form 3,4-dihydroxybenzoate. These diverse reactions all occur within a single polypeptide and are achieved through conformational rearrangements of the isoalloxazine ring and protein residues within the protein structure. In this review, we examine the complex dynamic behavior of the protein that enables regulated fast and specific catalysis to occur. Original research papers (principally from the past 15 years) provide the information that is used to develop a comprehensive overview of the catalytic process. Much of this information has come from detailed analysis of many specific mutants of the enzyme using rapid reaction technology, biophysical measurements, and high-resolution structures obtained by X-ray crystallography. We describe how three conformations of the enzyme provide a foundation for the catalytic cycle. One conformation has a closed active site for the conduct of the oxygen reactions, which must occur in the absence of solvent. The second conformation has a partly open active site for exchange of substrate and product, and the third conformation has a closed protein structure with the isoalloxazine ring rotated out to the surface for reaction with NADPH, which binds in a surface cleft. A fundamental feature of the enzyme is a H-bond network that connects the phenolic group of the substrate in the buried active site to the surface of the protein. This network serves to protonate and deprotonate the substrate and product in the active site to promote catalysis and regulate the coordination of conformational states for efficient catalysis.

Authors+Show Affiliations

Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, U.S. Gov't, P.H.S.
Review

Language

eng

PubMed ID

15581585

Citation

Entsch, Barrie, et al. "Protein Dynamics and Electrostatics in the Function of P-hydroxybenzoate Hydroxylase." Archives of Biochemistry and Biophysics, vol. 433, no. 1, 2005, pp. 297-311.
Entsch B, Cole LJ, Ballou DP. Protein dynamics and electrostatics in the function of p-hydroxybenzoate hydroxylase. Arch Biochem Biophys. 2005;433(1):297-311.
Entsch, B., Cole, L. J., & Ballou, D. P. (2005). Protein dynamics and electrostatics in the function of p-hydroxybenzoate hydroxylase. Archives of Biochemistry and Biophysics, 433(1), 297-311.
Entsch B, Cole LJ, Ballou DP. Protein Dynamics and Electrostatics in the Function of P-hydroxybenzoate Hydroxylase. Arch Biochem Biophys. 2005 Jan 1;433(1):297-311. PubMed PMID: 15581585.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Protein dynamics and electrostatics in the function of p-hydroxybenzoate hydroxylase. AU - Entsch,Barrie, AU - Cole,Lindsay J, AU - Ballou,David P, PY - 2004/07/29/received PY - 2004/12/8/pubmed PY - 2005/1/29/medline PY - 2004/12/8/entrez SP - 297 EP - 311 JF - Archives of biochemistry and biophysics JO - Arch Biochem Biophys VL - 433 IS - 1 N2 - para-Hydroxybenzoate hydroxylase is a flavoprotein monooxygenase that catalyzes a reaction in two parts: reduction of the enzyme cofactor, FAD, by NADPH in response to binding p-hydroxybenzoate to the enzyme, then oxidation of reduced FAD by oxygen to form a hydroperoxide, which oxygenates p-hydroxybenzoate to form 3,4-dihydroxybenzoate. These diverse reactions all occur within a single polypeptide and are achieved through conformational rearrangements of the isoalloxazine ring and protein residues within the protein structure. In this review, we examine the complex dynamic behavior of the protein that enables regulated fast and specific catalysis to occur. Original research papers (principally from the past 15 years) provide the information that is used to develop a comprehensive overview of the catalytic process. Much of this information has come from detailed analysis of many specific mutants of the enzyme using rapid reaction technology, biophysical measurements, and high-resolution structures obtained by X-ray crystallography. We describe how three conformations of the enzyme provide a foundation for the catalytic cycle. One conformation has a closed active site for the conduct of the oxygen reactions, which must occur in the absence of solvent. The second conformation has a partly open active site for exchange of substrate and product, and the third conformation has a closed protein structure with the isoalloxazine ring rotated out to the surface for reaction with NADPH, which binds in a surface cleft. A fundamental feature of the enzyme is a H-bond network that connects the phenolic group of the substrate in the buried active site to the surface of the protein. This network serves to protonate and deprotonate the substrate and product in the active site to promote catalysis and regulate the coordination of conformational states for efficient catalysis. SN - 0003-9861 UR - https://www.unboundmedicine.com/medline/citation/15581585/Protein_dynamics_and_electrostatics_in_the_function_of_p_hydroxybenzoate_hydroxylase_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0003-9861(04)00545-4 DB - PRIME DP - Unbound Medicine ER -