MOLECULAR-CLONING OF A LIGHT-INDUCIBLE GENE (LIPA) ENCODING A NOVEL PILIN FROM ARTHROBACTER-PHOTOGONIMOS

Development of pill on cells of Arthiobacter photogonimos is induced b y photo-oxidative conditions. The nucleotide sequence was determined o f a light-inducible gene (lipA) that encodes the precursor of a light- inducible pilin (designated LIP), a polypeptide of 212 amino acids. Th e N-terminal leader peptide includes a typical signal sequence with a consensus cleavage site for signal peptidase I after residue 28, which should generate N-terminal arginine. However, the next amino acid, al anine, is the N-terminal residue of the mature protein. The abundance of charged amino acids (27% of total), a calculated pi of 9.98, and re covery of mostly monomers when cells were washed with 1 M NaCl suggest that electrostatic interactions play a dominant role in association o f LIP, a novel mechanism for assembly of pill. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.