Apsychrotrophic bacteriumShewanellasp. strain SIB1 was grown at 4 and 20 C, and total soluble proteins extracted from the cells were analyzed by two-dimensional poly-acrylamide gel electrophoresis. Comparison ofthese pat-terns showed that the cellular content ofa protein with a molecular mass of28 kDa and an isoelectric point of four greatly increased at 4 C compared to that at 20 C. Determination ofthe N-terminal amino acid sequence, fol-lowed by the cloning and sequencing ofthe gene encoding this protein, revealed that this protein is a member ofthe FKBP family of proteins with an amino acid sequence identity of56% to Escherichia coliFKBP22. .
