Related Experiment Video

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Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells
05:58

Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells

Published on: February 24, 2026

Mycobacteriophage Lysin B is a novel mycolylarabinogalactan esterase

Kimberly Payne1, Qingan Sun, James Sacchettini

  • 1Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.

Molecular Microbiology
|June 27, 2009
PubMed

Insights

Mycobacteriophages use two enzymes, Lysin A and Lysin B, to break down bacterial cell walls. Lysin B is crucial for cleaving the outer membrane, aiding in efficient mycophage lysis.

Area of Science:

  • Microbiology
  • Structural Biology
  • Biochemistry

Background:

  • Mycobacteriophages infect Gram-positive bacteria, requiring unique lysis mechanisms.
  • Bacterial lysis involves degrading peptidoglycan and overcoming the mycolic acid-rich outer membrane.

Purpose of the Study:

  • To investigate the role and mechanism of Lysin B (LysB) in mycobacteriophage lysis.
  • To elucidate the structural features of LysB involved in substrate binding and activity.

Main Methods:

  • Structural analysis of D29 LysB.
  • Biochemical characterization of LysB activity.
  • Genetic analysis of a Giles DeltalysB mutant mycobacteriophage.

Main Results:

  • LysB is a mycolylarabinogalactan esterase that cleaves the mycolylarabinogalactan bond.
  • D29 LysB possesses an alpha/beta hydrolase fold with a lipid-binding domain.
  • A DeltalysB mutant showed defects in lysis timing and completion, though viable.

Conclusions:

  • LysB facilitates mycobacterial lysis by disrupting the outer membrane linkage.
  • LysB's unique structure enables it to target and cleave the mycobacterial outer membrane components.

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