PA3992

Gene Description

PA3992 encodes SltB3 (also called SltH), one of the eleven lytic transglycosylases of Pseudomonas aeruginosa and a member of the family 3 (GH103, MltB-like) group. The 448-residue precursor has a signal peptide, a catalytic SLT domain with a calcium-binding loop, and a C-terminal peptidoglycan-binding domain; the crystal structure shows four domains arranged as a ring through which the glycan strand threads. SltB3 is an exolytic enzyme that removes the terminal disaccharide from peptidoglycan strands, needing at least four sugars and processing strands of up to 20 sugars, and releases N-acetylglucosamine-1,6-anhydro-N-acetylmuramic acid as the final product. It contributes to periplasmic peptidoglycan turnover during cell wall recycling.

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0008933 peptidoglycan lytic transglycosylase activity	IBA GO_REF:0000033	ACCEPT	Summary: IBA from the MltB-like family node PTN002410022, seeded by E. coli MltB (P41052) and the three P. aeruginosa paralogs, including this gene. Reason: SltB3 is shown biochemically to be a lytic transglycosylase, and the IBD also stands on E. coli MltB. Supporting Evidence: PMID:27035839 The ultimate product of the reaction is N-acetylglucosamine-1,6-anhydro-N-acetylmuramic acid. file:PSEAE/PA3992/PA3992-uniprot.txt IPR011970; MltB_2
GO:0008933 peptidoglycan lytic transglycosylase activity	IDA PMID:27035839 Turnover of Bacterial Cell Wall by SltB3, a Multidomain Lyti...	ACCEPT	Summary: PseudoCAP IDA seed of PTN002410022 from the SltB3 biochemistry and structure paper. Reason: Purified SltB3 cleaves peptidoglycan to GlcNAc-1,6-anhydroMurNAc with measured kinetics; the term includes exolytic activity. Seed verdict SOUND. Supporting Evidence: PMID:27035839 The ultimate product of the reaction is N-acetylglucosamine-1,6-anhydro-N-acetylmuramic acid. PMID:27035839 The purified recombinant SltB3 turned over 1 (Figure 2B), with the following kinetics parameters
GO:0009253 peptidoglycan catabolic process	IBA GO_REF:0000033	ACCEPT	Summary: IBA peptidoglycan catabolic process from PTN002410022, seeded by E. coli MltB. Reason: SltB3 degrades peptidoglycan strands to anhydro-disaccharides, a catabolic step of peptidoglycan. Supporting Evidence: PMID:27035839 The ultimate product of the reaction is N-acetylglucosamine-1,6-anhydro-N-acetylmuramic acid.
GO:0009254 peptidoglycan turnover	IDA PMID:27035839 Turnover of Bacterial Cell Wall by SltB3, a Multidomain Lyti...	ACCEPT	Summary: PseudoCAP IDA to peptidoglycan turnover from the same paper. Reason: The enzyme itself performs the breakdown step of peptidoglycan turnover, and the paper places it in periplasmic cell wall recycling. The process is consistent with the amidases AmpD, AmpDh2 and AmpDh3 reviewed in this organism. Supporting Evidence: PMID:27035839 The breakdown of the peptidoglycan for the recycling events is performed by lytic transglycosylases (LTs)

Core Functions

Exolytic lytic transglycosylase that removes terminal GlcNAc-1,6-anhydroMurNAc disaccharides from peptidoglycan strands in the periplasm, contributing to cell wall turnover and recycling.

Molecular Function:

peptidoglycan lytic transglycosylase activity

Directly Involved In:

peptidoglycan turnover peptidoglycan catabolic process

Supporting Evidence:

PMID:27035839
The ultimate product of the reaction is N-acetylglucosamine-1,6-anhydro-N-acetylmuramic acid.

Gene Description

Existing Annotations Review

Core Functions

Exolytic lytic transglycosylase that removes terminal GlcNAc-1,6-anhydroMurNAc disaccharides from peptidoglycan strands in the periplasm, contributing to cell wall turnover and recycling.

References

📚 Additional Documentation

Notes

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