Dataset Information

X-ray Structure of Catenated Lytic Transglycosylase SltB1.

ABSTRACT: Formation of catenanes by proteins is rare, with few known examples. We report herein the X-ray structure of a catenane dimer of lytic transglycosylase SltB1 of Pseudomonas aeruginosa. The enzyme is soluble and exists in the periplasmic space, where it modifies the bacterial cell wall. The catenane dimer exhibits the protein monomers in a noncovalent chain-link arrangement, whereby a stretch of 51 amino acids (to become a loop and three helices) from one monomer threads through the central opening of the structure of the partner monomer. The protein folds after threading in a manner that leaves two helices (?1 and ?2) as stoppers to impart stability to the dimer structure. The symmetric embrace by the two SltB1 molecules occludes both active sites entirely, an arrangement that is sustained by six electrostatic interactions between the two monomers. In light of the observation of these structural motifs in all members of Family 3 lytic transglycosylases, catenanes might be present for those enzymes, as well. The dimeric catenane might represent a regulated form of SltB1.

SUBMITTER: Dominguez-Gil T

PROVIDER: S-EPMC6860912 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

X-ray Structure of Catenated Lytic Transglycosylase SltB1.

Domínguez-Gil Teresa T Molina Rafael R Dik David A DA Spink Edward E Mobashery Shahriar S Hermoso Juan A JA

Biochemistry 20171116 48

Formation of catenanes by proteins is rare, with few known examples. We report herein the X-ray structure of a catenane dimer of lytic transglycosylase SltB1 of Pseudomonas aeruginosa. The enzyme is soluble and exists in the periplasmic space, where it modifies the bacterial cell wall. The catenane dimer exhibits the protein monomers in a noncovalent chain-link arrangement, whereby a stretch of 51 amino acids (to become a loop and three helices) from one monomer threads through the central openi ...[more]

PMID: 29131935

Similar Datasets

Project description:In this work, we have characterized the soluble lytic transglycosylase (SltF) from Rhodobacter sphaeroides that interacts with the scaffolding protein FlgJ in the periplasm to open space at the cell wall peptidoglycan heteropolymer for the emerging rod. The characterization of the genetic context of flgJ and sltF in alphaproteobacteria shows that these two separate genes coexist frequently in a flagellar gene cluster. Two domains of unknown function in SltF were studied, and the results show that the deletion of a 17-amino-acid segment near the N terminus does not show a recognizable phenotype, whereas the deletion of 47 and 95 amino acids of the C terminus of SltF disrupts the interaction with FlgJ without affecting the transglycosylase catalytic activity of SltF. These mutant proteins are unable to support swimming, indicating that the physical interaction between SltF and FlgJ is central for flagellar formation. In a maximum likelihood tree of representative lytic transglycosylases, all of the flagellar SltF proteins cluster in subfamily 1F. From this analysis, it was also revealed that the lytic transglycosylases related to the type III secretion systems present in pathogens cluster with the closely related flagellar transglycosylases.IMPORTANCE Flagellar biogenesis is a highly orchestrated event where the flagellar structure spans the bacterial cell envelope. The rod diameter of approximately 4 nm is larger than the estimated pore size of the peptidoglycan layer; hence, its insertion requires the localized and controlled lysis of the cell wall. We found that a 47-residue domain of the C terminus of the lytic transglycosylase (LT) SltF of R. sphaeroides is involved in the recognition of the rod chaperone FlgJ. We also found that in many alphaproteobacteria, the flagellar cluster includes a homolog of SltF and FlgJ, indicating that association of an LT with the flagellar machinery is ancestral. A maximum likelihood tree shows that family 1 of LTs segregates into seven subfamilies.

Dataset Information

X-ray Structure of Catenated Lytic Transglycosylase SltB1.

Publications

X-ray Structure of Catenated Lytic Transglycosylase SltB1.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets