CRYSTAL-STRUCTURE OF PARA-HYDROXYBENZOATE HYDROXYLASE

[摘要] The structure of the enzyme p-hydroxybenzoate hydroxylase (EC 1.14.13.2) [Pseudomonas fluorescens] in a complex with its substrate was determined at a resolution of 2.5 .ANG.. The MW is 43,000 and the dimensions of 1 molecule are approximately 70 .ANG. .times. 50 .ANG. .times. 45 .ANG.. The crystal structure contains dimers of these molecules. Approximately 16% of the residues occur in .beta.-sheets and 26% in .alpha.-helices. The molecule can be divided into 3 domains. The active site, near the isoalloxazine ring, is formed by side-chains of the 3 domains. The N-5 edge of the isoalloxazine ring points to p-hydroxybenzoate, which is bound in a deep cleft.