Possible involvement of an FKBP family member protein from a psychrotrophic bacterium Shewanella sp. SIB1 in cold‐adaptation

Abstract

A psychrotrophic bacterium Shewanella sp. strain SIB1 was grown at 4 and 20°C, and total soluble proteins extracted from the cells were analyzed by two-dimensional polyacrylamide gel electrophoresis. Comparison of these patterns showed that the cellular content of a protein with a molecular mass of 28 kDa and an isoelectric point of four greatly increased at 4°C compared to that at 20°C. Determination of the N-terminal amino acid sequence, followed by the cloning and sequencing of the gene encoding this protein, revealed that this protein is a member of the FKBP family of proteins with an amino acid sequence identity of 56% to Escherichia coli FKBP22. This protein was overproduced in E. coli in a His-tagged form, purified, and analyzed for peptidyl-prolyl cis-trans isomerase activity.When this activity was determined by the protease coupling assay using N-succinyl-Ala-Leu-Pro-Phe-p-nitroanilide as a substrate at various temperatures, the protein exhibited the highest activity at 10°C with a k cat /K m value of 0.87 lM . When the peptidyl-prolyl cis-trans isomerase activity was determined by the RNase T 1 refolding assay at 10 and 20°C, the protein exhibited higher activity at 10°C with a k cat /K m value of 0.50 lM . These k cat /K m values are lower but comparable to those of E. coli FKBP22. We propose that a FKBP family protein is involved in cold-adaptation of psychrotrophic bacteria.

A Legionella pneumophila Peptidyl-Prolyl cis - trans Isomerase Present in Culture Supernatants Is Necessary for Optimal Growth at Low Temperatures

“…Finally, PpiB, whether as an isomerase or as a chaperone, might promote the functioning of a secretion apparatus. There are examples of PPIases that are secreted and surface expressed by microbes, such as HP0175 of Helicobacter pylori and Mip of L. pneumophila (1,9,30), and there are PPIases that have ben previously linked to low-temperature adaptation, such as cell-associated PpiB of Bacillus subtilis, FKBP of Shewanella sp., and RotA of Erwinia chrysanthemi (2,32,43). But the connection that we uncovered between a secreted PPIase and low-temperature growth is a novel observation.…”

Defining the Functional Potential and Active Community Members of a Sediment Microbial Community in a High-Arctic Hypersaline Subzero Spring

“…Microorganisms that sustain metabolic processes at cold temperatures produce cold acclimation and cold shock proteins involved in DNA replication (GyrA, RecA, and DnaA) (77)(78)(79) (79,(85)(86)(87), pyruvate metabolism (AceE and AceF) (88,89), and unsaturated fatty acid metabolism (fatty acid desaturases; DnaJ) (1,(90)(91)(92). Genes encoding such proteins were identified as containing cold adaptation features within the LH metagenome and originated mostly from Proteobacteria, Bacteroidetes, and Cyanobacteria (see Table S6 in the supplemental material).…”

A Novel Class of Dual-family Immunophilins

“…The chaperone assay involved refolding of RNase T1 (18). In this procedure, RNase T1 (50 M) was first unfolded by incubating at 25°C for 3 h in buffer A (50 mM Tris-Cl (pH 8.0), 1 mM EDTA) containing 6 M guanidine hydrochloride.…”