In:
Microbial Physiology, S. Karger AG, Vol. 13, No. 1-3 ( 2007), p. 65-75
Abstract:
When carrying out a proteome analysis with a 〈 i 〉 ptsH3 〈 /i 〉 mutant of 〈 i 〉 Lactobacillus casei 〈 /i 〉 , we found that the cold shock protein CspA was significantly overproduced compared to the wild-type strain. We also noticed that CspA and CspB of 〈 i 〉 L. casei 〈 /i 〉 and CSPs from other organisms exhibit significant sequence similarity to the C-terminal part of EIIA 〈 sup 〉 Glc 〈 /sup 〉 , a glucose-specific component of the phosphoenolpyruvate:sugar phosphotransferase system. This similarity suggested a direct interaction of HPr with CSPs, as histidyl-phosphorylated HPr has been shown to phosphorylate EIIA 〈 sup 〉 Glc 〈 /sup 〉 in its C-terminal part. We therefore compared the cold shock response of several carbon catabolite repression mutants to that of the wild-type strain. Following a shift from 37°C to lower temperatures (20, 15 or 10°C), all mutants showed significantly reduced growth rates. Moreover, glucose-grown mutants unable to form P-Ser-HPr 〈 i 〉 (ptsH1, hprK) 〈 /i 〉 exhibited drastically increased sensitivity to freeze/thaw cycles. However, when the same mutants were grown on ribose or maltose, they were similarly resistant to freezing and thawing as the wild-type strain. Although subsequent biochemical and genetic studies did not allow to identify the form of HPr implicated in the resistance to cold and freezing conditions, they strongly suggested a direct interaction of HPr or one of its phospho-derivatives with CspA and/or another, hitherto undetected cold shock protein in 〈 i 〉 L. casei 〈 /i 〉 .
Type of Medium:
Online Resource
ISSN:
2673-1665
,
2673-1673
Language:
English
Publisher:
S. Karger AG
Publication Date:
2007
detail.hit.zdb_id:
3042601-7
Bookmarklink