首页 | 本学科首页   官方微博 | 高级检索  
     


Methionine biosynthesis in higher plants: biochemical and molecular characterization of the transsulfuration pathway enzymes
Affiliation:1. Univ. Lille, INSERM, Institut Pasteur de Lille, U1177, F-59000 Lille, France;2. Aix Marseille Univ. CNRS, AFMB UMR 7257, Marseille, France;3. Univ. Bordeaux, Allée Geoffroy St Hilaire, 33615 Pessac, France;4. INSERM, LAMC, UMR 1029, Allée Geoffroy St Hilaire, 33615 Pessac, France;1. Department of Computer Science, University of Bath, Bath, United Kingdom;2. Department of Psychology, University of Bath, Bath, United Kingdom;3. Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom;4. Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States;5. Licenciatura en Ciencias Genómicas, UNAM, CP62210, Cuernavaca, México;6. Instituto de Ecología, UNAM, Ciudad Universitaria, CP04510, Ciudad de México, México;7. Centre for Health and Cognition, Bath Spa University, Bath, United Kingdom
Abstract:In plants, the transfer of the sulfur atom between cysteine and homocysteine, the direct precursor of methionine, is ensured by two chloroplastic enzymes, cystathionine γ-synthase and cystathionine β-lyase. These proteins have been purified to homogeneity from spinach chloroplasts and their biochemical properties determined. Cystathionine γ-synthase and cystathionine β-lyase are tetramers and are typical pyridoxal 5′-phosphate-dependent proteins. These enzymes are targets for the potent inhibitors of methionine synthesis that are lethal for plants. An Arabidopsis thaliana cDNA encoding chloroplastic cystathionine β-lyase was isolated by functional complementation of a bacterial mutant and cloned in a pET expression vector in order to transform Escherichia coli cells. Preliminary observations of the active site of the purified recombinant enzyme have been performed by characterization of the interaction between i) pyridoxal 5′-phosphate and the polypeptide chain, and ii) the active site-directed inhibitor aminoethoxyvinylglycine and the bound cofactor. This study will be developed further by crystallographic analyses.
Keywords:
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号