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Molecular analysis of the hsp (groE) operon of Leptospira interrogans serovar copenhageni
Author(s) -
Ballard S. A.,
Segers R. P. A. M.,
BleuminkPluym N.,
Fyfe J.,
Faine S.,
Adler B.
Publication year - 1993
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1993.tb01617.x
Subject(s) - biology , operon , microbiology and biotechnology , orfs , genetics , ecori , open reading frame , heat shock protein , gene , nucleic acid sequence , peptide sequence , restriction enzyme , escherichia coli
Summary A chromosomal gene library of Leptospira interrogans serovar copenhageni strain Wijnberg was constructed in phage lambda gt11. Plaque immunoassay with RαP64 antiserum identified one clone expressing a putative groEL homologue. DNA sequence analysis of the 2.4kb Eco RI‐ Bam HI cloned fragment from strain Wijnberg revealed two open reading frames encoding polypeptides of 10.5kDa (Hsp10) and 58kDa (Hsp58). Sequence comparison of the deduced amino acid sequences of these ORFs confirmed the operon as the groE equivalent of Leptospira. Transcriptional analysis suggested that this operon is primarily under the control of an Eσ70 promoter element. However, both Hsp10 and Hsp58 were overexpressed under heat‐shock conditions as determined by [ 35 S]‐methionine pulse labelling experiments. As no functional heat‐shock promoter could be identified, a 9bp inverted repeat, located between the transcription and translation start sites, may play a role in the upregulation of this operon under heat‐shock conditions, similar to mechanisms described for several Gram‐positive organisms.