Actin's prokaryotic homologs.
Actin is one of the most abundant and conserved eukaryotic proteins. Remarkably, two prokaryotic homologs of actin, MreB and ParM, have only recently been identified. MreB and ParM polymerize into filaments and play important roles in the control of bacterial cell shape and plasmid segregation, respectively. Whereas the eukaryotic actins display a remarkable degree of conservation (e.g. no amino acid changes in muscle actin from chickens to humans), the two bacterial proteins have as much sequence similarity to each other ( approximately 11% sequence identity) as they do to actin. It is possible that the interesting properties of eukaryotic F-actin may account for the unusual degree of conservation among the actins, whereas the bacterial proteins have had fewer constraints over the course of evolution.
Department of Biochemistry and Molecular Genetics, University of Virginia Health Sciences Center, Box 800733, Charlottesville 22908-0733, USA. egelman@virginia.edu
Edward H
EH
Egelman
D000199:Actins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D011387:Prokaryotic Cells / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D017385:Sequence Homology; D013045:Species Specificity
D000199:Actins; D029968:Escherichia coli Proteins; C471255:ParM protein, E coli; C078473:MreB protein, E coli