Expression and characterization of a magnetosome-associated protein, TPR-containing MAM22, in Escherichia coli

A magnetosome-associated protein, MAM22, contains a TPR domain (five TPR motifs and one protein putative TPR motif) that has been known to mediate protein-protein interactions. We expressed the mam22 gene in Escherichia coli and found that the purified MAM22 was reversibly self-aggregated by NaCl. The structural model oof MAM22 which has been proposed on the basis of the crystal structure of the N-terminal TPR domain of a human Ser/Thr protein phosphatase suggests the novel hydrophobic colloidal features of MAM22 with TPR motifs. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.