Structure of yeast 5-aminolaevulinic acid dehydratase complexed with the inhibitor 5-hydroxylaevulinic acid

P T Erskine,S P Wood,M J Warren,J B Cooper,G D E Beaven,R Newbold,R Gill,A A Brindley,L Coates,R Neier,F Stauffer,A Coker,P M Shoolingin-Jordan

doi:10.1107/s0907444905018834

Abstract

The X-ray structure of the enzyme 5-aminolaevulinic acid dehydratase (ALAD) from yeast complexed with the competitive inhibitor 5-hydroxylaevulinic acid has been determined at a resolution of 1.9 A. The structure shows that the inhibitor is bound by a Schiff-base link to one of the invariant active-site lysine residues (Lys263). The inhibitor appears to bind in two well defined conformations and the interactions made by it suggest that it is a very close analogue of the substrate 5-aminolaevulinic acid (ALA).

Highlights

The enzyme 5-aminolaevulinic acid dehydratase (ALAD, known as porphobilinogen synthase; EC 4.2.1.24) catalyses an early step in the biosynthesis of tetrapyrroles involving the condensation of two 5-aminolaevulinic acid (ALA) molecules to form the pyrrole porphobilinogen (PBG; see Fig. 1; Jordan, 1991, 1994; Warren & Scott, 1990; Jaffe, 1995, 2003)
We report on the high-resolution X-ray structure of the inhibitor 5-hydroxylaevulinic acid (Fig. 3), which is a close analogue of the substrate ALA, bound to the yeast ALAD enzyme
Crystals of yeast ALAD with 5-hydroxylaevulinic acid bound were obtained by co-crystallizing the enzyme in the presence of the inhibitor

Summary

Biological Crystallography

ASchool of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, England, bSchool of Biological Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, England, and cInstitut de Chimie, Universitede Neuchatel, Avenue Bellevaux 51, Case Postale 2, CH-2007 Neuchatel 7, Switzerland. The X-ray structure of the enzyme 5-aminolaevulinic acid dehydratase (ALAD) from yeast complexed with the competitive inhibitor 5-hydroxylaevulinic acid has been determined at a resolution of 1.9 A. The structure shows that the inhibitor is bound by a Schiff-base link to one of the invariant active-site lysine residues (Lys263). The inhibitor appears to bind in two well defined conformations and the interactions made by it suggest that it is a very close analogue of the substrate 5-aminolaevulinic acid (ALA)

Introduction

Materials and methods

Findings

Results and discussion