Overexpression of cold shock protein A of Psychromonas arctica KOPRI 22215 confers cold-resistance.
A polar bacterium was isolated from Arctic sea sediments and identified as Psychromonas artica, based on 16S rDNA sequence. Psychromonas artica KOPRI 22215 has an optimal growth temperature of 10 degrees C and a maximum growth temperature of 25 degrees C, suggesting this bacterium is a psychrophile. Cold shock proteins (Csps) are induced upon temperature downshift by more than 10 degrees C. Functional studies have researched mostly Csps of a mesophilic bacterium Escherichia coli, but not on those of psychrophilic bacteria. In an effort to understand the molecular mechanisms of psychrophilic bacteria that allow it withstand freezing environments, we cloned a gene encoding a cold shock protein from P. artica KOPRI 22215 (CspA(Pa)) using the conserved sequences in csp genes. The 204 bp-long ORF encoded a protein of 68 amino acids, sharing 56% homology to previously reported E. coli CspA protein. When CspA(Pa) was overexpressed in E. coli, it caused cell growth-retardation and morphological elongation. Interestingly, overexpression of CspA(Pa) drastically increased the host's cold-resistance by more than ten times, suggesting the protein aids survival in polar environments.
Jung
Youn Hong
YH
Department of Molecular Biology, Sejong University, 98 Gunja-dong, Kwangjin-gu, Seoul, 143-747, Korea.
Yi
Ji-Yeun
JY
Jung
Hyun Jung
HJ
Lee
Yoo Kyung
YK
Lee
Hong Kum
HK
Naicker
Mahendran Chinnamara
MC
Uh
Ji-hyun
JH
Jo
I Seul
IS
Jung
Eun Jung
EJ
Im
Hana
H
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D003080:Cold Temperature; D020563:Gammaproteobacteria / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
D001426:Bacterial Proteins; C062260:cold shock protein CS7.4, Bacteria