7QVD

X-ray structure of the lytic transglycosylase SltB2 from Pseudomonas aeruginosa

Summary for 7QVD

• Entry DOI: 10.2210/pdb7qvd/pdb
• Descriptor: Lytic murein transglycosylase, CALCIUM ION (3 entities in total)
• Functional Keywords: lytic transglycosylase, hydrolase
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 1
• Total formula weight: 40934.14

Authors

Batuecas, M.T.,Miguel-Ruano, V.,Hermoso, J.A. (deposition date: 2022-01-21, release date: 2023-08-16, Last modification date: 2026-02-25)

Primary citation

Miguel-Ruano, V.,Batuecas, M.T.,Lastochkin, E.,Dominguez-Gil, T.,Molina, R.,Mobashery, S.,Hermoso, J.A.
Structural Characterization of Lytic Transglycosylase SltB2 of Pseudomonas aeruginosa.
Acs Omega, 10:48385-48394, 2025

PubMed Abstract: Lytic transglycosylases (LTs) belong to a family of enzymes that turnover the bacterial cell-wall peptidoglycan through a nonhydrolytic cleavage of the β(1-4) glycosidic bond, generating a hallmark 1,6-anhydromuramyl moiety in the reaction products. LTs are essential for numerous cellular processes, including cell-wall maturation, peptidoglycan recycling, cell division, and the assembly of multiprotein complexes. Their functional diversity underscores their biological significance. Family 3 LTs are distinguished by their EF-hand Ca-binding motif and are classified into two subfamilies. Subfamily 3B members, including SltB2, possess a peptidoglycan-binding domain absent in subfamily 3A. In this study, we present the structural characterization of SltB2. The high-resolution crystal structure of SltB2 reveals a unique modular architecture shaped by the specific arrangement of its PG-binding domain and distinct differences in the organization of key residues surrounding the catalytic Glu residue compared to other family 3 members. A model of interaction between SltB2 and the peptidoglycan is proposed, which accounts for the enzyme's tolerance to peptide stems and reveals particular features at site +2, due to the unique arrangement of the PG-binding domain, explaining its preferred exolytic activity. Comparative structural analyses of Family 3 LTs provide insights into substrate recognition and enzymatic function, advancing our understanding of bacterial cell-wall remodeling mechanisms.

PubMed: 41141816
DOI: 10.1021/acsomega.5c05747

Experimental method

X-RAY DIFFRACTION (1.7 Å)