当前位置： SCI文献检索 > JOURNAL OF BACTERIOLOGY期刊下所有文献 > Structure and function of cold shock proteins in archaea.

Structure and function of cold shock proteins in archaea.

Abstract：

:Archaea are abundant and drive critical microbial processes in the Earth's cold biosphere. Despite this, not enough is known about the molecular mechanisms of cold adaptation and no biochemical studies have been performed on stenopsychrophilic archaea (e.g., Methanogenium frigidum). This study examined the structural and functional properties of cold shock proteins (Csps) from archaea, including biochemical analysis of the Csp from M. frigidum. csp genes are present in most bacteria and some eucarya but absent from most archaeal genome sequences, most notably, those of all archaeal thermophiles and hyperthermophiles. In bacteria, Csps are small, nucleic acid binding proteins involved in a variety of cellular processes, such as transcription. In this study, archaeal Csp function was assessed by examining the ability of csp genes from psychrophilic and mesophilic Euryarchaeota and Crenarchaeota to complement a cold-sensitive growth defect in Escherichia coli. In addition, an archaeal gene with a cold shock domain (CSD) fold but little sequence identity to Csps was also examined. Genes encoding Csps or a CSD structural analog from three psychrophilic archaea rescued the E. coli growth defect. The three proteins were predicted to have a higher content of solvent-exposed basic residues than the noncomplementing proteins, and the basic residues were located on the nucleic acid binding surface, similar to their arrangement in E. coli CspA. The M. frigidum Csp was purified and found to be a single-domain protein that folds by a reversible two-state mechanism and to exhibit a low conformational stability typical of cold-adapted proteins. Moreover, M. frigidum Csp was characterized as binding E. coli single-stranded RNA, consistent with its ability to complement function in E. coli. The studies show that some Csp and CSD fold proteins have retained sufficient similarity throughout evolution in the Archaea to be able to function effectively in the Bacteria and that the function of the archaeal proteins relates to cold adaptation. The initial biochemical analysis of M. frigidum Csp has developed a platform for further characterization and demonstrates the potential for expanding molecular studies of proteins from this important archaeal stenopsychrophile.

journal_name

J Bacteriol

journal_title

Journal of bacteriology

authors

Giaquinto L,Curmi PM,Siddiqui KS,Poljak A,DeLong E,DasSarma S,Cavicchioli R

doi

10.1128/JB.00395-07

subject

Has Abstract

pub_date

2007-08-01 00:00:00

pages

5738-48

issue

eissn

0021-9193

issn

1098-5530

pii

JB.00395-07

journal_volume

189

pub_type

杂志文章

在线工具

Structure and function of cold shock proteins in archaea.