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Location of enzymatic and DNA‐binding domains on E. coli protease La
Author(s) -
Baker Michael E.
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)81155-x
Subject(s) - bacillus licheniformis , protease , serine protease , biochemistry , enzyme , escherichia coli , dna , biology , serine , residue (chemistry) , amino acid , binding site , microbiology and biotechnology , bacillus subtilis , bacteria , genetics , gene
Escherichia coli protease La is an ATP‐dependent enzyme that has a DNA‐binding site. The locations of the enzymatic and DNA‐binding sites are not known. We report that a 75‐residue segment at the carboxy‐terminus of the protease La is similar to part of Bacillus licheniformis β‐lactamase, a serine enzyme. The comparison score is 8.2 standard deviations higher than that obtained with 10 000 comparisons of randomized sequences of these segments. The probability of obtaining such a score by chance is 1.2 × 10 −16 . We also find that a 107‐residue segment in the amino‐terminus half of protease La is similar to part of the sopB protein, a DNA‐binding protein of the plasmid F of E. coli . The comparison score for these segments is 8 standard deviations ( P = 6 × 10 −16 ). These strong amino acid sequence similarities suggest the locations of the catalytic serine and the DNA‐binding domains of protease La.