Structural Investigations and Identification of the Extracellular Bacteriolytic Endopeptidase L1 from Lysobacter sp. XL1

T. A. Muranova^1*, L. A. Krasovskaya¹, I. M. Tsfasman², O. A. Stepnaya², and I. S. Kulaev²

¹Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia; fax: (027) 790-527; E-mail: Muranova@fibkh.serpukhov.su

²Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia; fax: (7-095) 923-3602; E-mail: Kulaev@ibpm.serpukhov.su

^* To whom correspondence should be addressed.

Received June 17, 2003; Revision received July 9, 2003

---

The N-terminal amino acid sequence (23 amino acid residues) and the amino acid composition of the extracellular bacteriolytic enzyme L1 of 21 kD from the bacterium Lysobacter sp. XL1 have been determined. The enzyme was hydrolyzed by trypsin, the resulting peptides were isolated, and their primary structures were determined. A high extent of homology (92%) of the N-terminal amino acid sequence and the primary structure of isolated peptides of the enzyme L1 (62 amino acid residues or 31% of protein sequence) to the corresponding sites of alpha-lytic proteinases (EC 3.4.21.12) of Lysobacter enzymogenes and Achromobacter lyticus was found. These data allowed identification of the endopeptidase L1 of Lysobacter sp. XL1 as alpha-lytic proteinase EC 3.4.21.12.

---

KEY WORDS: lytic endopeptidase, primary structure, Lysobacter sp., alpha-lytic proteinase

---