The Malonate Decarboxylase Operon of Acinetobacter calcoaceticus KCCM 40902 Is Regulated by Malonate and the Transcriptional Repressor MdcY

Author:

Koo Jae Hyung1,Cho Ick Hyun1,Kim Yu Sam1

Affiliation:

1. Department of Biochemistry, College of Science, Protein Network Research Center, Institute of Bioscience and Biotechnology, Yonsei University, Seoul 120-749, Korea

Abstract

ABSTRACT A regulatory gene-like open reading frame oriented oppositely to mdcL, coined mdcY , was found upstream from the structural genes of the mdcLMACDEGBH operon in Acinetobacter calcoaceticus KCCM 40902. To elucidate the function of this gene, mdcY was expressed in Escherichia coli , and the MdcY protein was purified to homogeneity. Its DNA binding activity and binding site were examined by gel retardation and footprinting assays in vitro and by site-directed mutagenesis of the binding sites in vivo. The regulator bound target DNA regardless of the presence of malonate, and the binding site was found centered at −65 relative to the mdcL transcriptional start site and contains a 12-bp palindromic structure (5′-ATTGTA/TACAAT-3′). Using a promoter fusion to the reporter gene luc , we found that the promoter P mdcY is negatively regulated by MdcY independent of malonate. However, the promoter P mdcL recovered its activity in the presence of malonate. When mdcY was introduced into A. calcoaceticus KCCM 40902 in which the gene is inactivated by an IS 3 family element, malonate decarboxylase was significantly repressed in cultures growing in acetate, succinate, or Luria-Bertani medium. However, in cells growing in malonate, malonate decarboxylase was induced, indicating that MdcY is a transcriptional repressor and that malonate or a product resulting from malonate metabolism should be the intracellular inducer of the mdc operon.

Publisher

American Society for Microbiology

Subject

Molecular Biology,Microbiology

Reference32 articles.

1. Transcriptional Regulation of the Streptococcus mutans gal Operon by the GalR Repressor

2. Sequence of a gene cluster from Malonomonas rubra encoding components of the malonate decarboxylase Na+ pump and evidence for their function;Berg M.;Eur. J. Biochem.,1997

3. Assays for malonate decarboxylase;Byun H. S.;Anal. Biochem.,1994

4. Metabolic routes of malonate in Pseudomonas fluorescens and Acinetobacter calcoaceticus;Byun H. S.;J. Biochem. Mol. Biol.,1995

5. Gel retardation;Carey J.;Methods Enzymol.,1991

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3