IDENTIFICATION OF A 180KD PROTEIN IN ESCHERICHIA-COLI RELATED TO A YEAST HEAVY-CHAIN MYOSIN

A high molecular‐weight protein from Escherichia coli sharing structural ho mo logy at the protein level with a yeast heavy‐chain myosin encoded by the MYO1 gene is described. This 180kD protein (180‐HMP) can be enriched in cell fractions following the procedure normally utilized for the purification of non‐muscle myosins. In Western blots this protein cross‐reacts with a monoclonal antibody against yeast heavy‐chain myosin. Moreover, antibodies raised against the 180kD protein cross‐react with the yeast myosin and with a myosin heavy chain from chicken. Recognition by anti‐180‐HMP antibodies of an overexpressed fragment of yeast myosin encoded by MYO1 allows the localization of one of the shared epitopes to a specific region around the ATP binding site of the yeast myosin heavy chain. The existence of a high molecular‐weight protein with structural similarity to myosin in E. coli raises the possibility that such a protein might generate the force required for movement in processes such as nucleoid segregation and cell division. Copyright © 1990, Wiley Blackwell. All rights reserved