caa a22 4500 475745914 CHVBK 20180406123513.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1007/s002849910047 doi (NATIONALLICENCE)springer-10.1007/s002849910047 Identification of a lexA Gene in, and Construction of a lexA Mutant of, Xanthomonas campestris pv. citri [Elektronische Daten] [Mei-Kwei Yang, Pei-I Wu, Yen-Chun Yang] Abstract.: The lexA gene of Xanthomonas campestris pathovar citri (X.c. pv. citri) was cloned and sequenced. The 639-bp open reading frame encodes a protein of 213 amino acids that shares substantial sequence homology with the products of previously characterized lexA genes, sharing 46% identity with the LexA protein of Escherichia coli. Amino acids required for autocatalytic cleavage of LexA are conserved in the X.c. pv. citri protein, whereas domains thought to mediate DNA binding differ markedly from those of LexA proteins from E. coli and other bacteria. The X.c. pv. citri LexA protein was overexpressed in E. coli, and SDS-polyacrylamide gel electrophoresis revealed a molecular size of 23 kDa for the purified protein. A lexA mutant of X.c. pv. citri was constructed by gene replacement, and the basal level of recA expression in this mutant was shown to be similar to that for wild-type cells exposed to a DNA-damaging agent. These results indicate that LexA functions as a repressor of recA expression in X.c. pv. citri. Springer-Verlag New York Inc., 2000 Yang Mei-Kwei Department of Biology, Fu Jen University, 510 Chun-Chen Road, Taipei 242, Taiwan, Republic of China, TW aut Wu Pei-I Department of Biology, Fu Jen University, 510 Chun-Chen Road, Taipei 242, Taiwan, Republic of China, TW aut Yang Yen-Chun Department of Biology, Fu Jen University, 510 Chun-Chen Road, Taipei 242, Taiwan, Republic of China, TW aut https://doi.org/10.1007/s002849910047 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002849910047 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yang Mei-Kwei Department of Biology, Fu Jen University, 510 Chun-Chen Road, Taipei 242, Taiwan, Republic of China, TW aut NATIONALLICENCE 700 1- Wu Pei-I Department of Biology, Fu Jen University, 510 Chun-Chen Road, Taipei 242, Taiwan, Republic of China, TW aut NATIONALLICENCE 700 1- Yang Yen-Chun Department of Biology, Fu Jen University, 510 Chun-Chen Road, Taipei 242, Taiwan, Republic of China, TW aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer