Location of enzymatic and DNA‐binding domains on E. coli protease La

FEBS Letters

Baker, Michael E.¹ 

[1] Department of Medicine, M-023, University of California, San Diego, La Jolla, CA 92093, USA

关键词: Protease La;    ATP-dependent protease;    DNA-binding protease;   

DOI  :  10.1016/0014-5793(89)81155-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown