The actin-polymerization protein from Listeria ivanovii is a large repeat protein which shows only limited amino acid sequence homology to ActA from Listeria monocytogenes.
Within infected eukaryotic cells the two pathogenic Listeria species, L. monocytogenes and L. ivanovii, induce polymerization of cellular actin and the formation of a propulsive actin tail at one bacterial pole. For L. monocytogenes it has been shown that the product of the listerial actA gene is required for this process which is regarded as a model for actin-based motility. We have now cloned and sequenced a functionally analogous gene from L. ivanovii; its product, as deduced from the DNA sequence, is considerably larger (108 kDa) than L. monocytogenes ActA (67 kDa) and shares only a limited amino acid sequence homology (46% similarity on average) with the latter protein. This is the first example of a virulence gene product from L. ivanovii which is significantly different from its L. monocytogenes counterpart. Comparison of the two ActA proteins gives new insight into the structure of this class of actin-polymerization proteins, in particular with respect to their proline-rich repeat region.
Kreft
J
J
Theodor-Boveri-Institut für Biowissenschaften (Biozentrum), Universität Würzburg, Lehrstuhl Mikrobiologie, Germany.
Dumbsky
M
M
Theiss
S
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D008087:Listeria / Q000737:chemistry / Q000235:genetics*; D008089:Listeria monocytogenes / Q000737:chemistry / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D008840:Microfilament Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; C072980:actA protein, Listeria monocytogenes