Pathway · 7 proteins
Wall synthesis and remodeling
Transpeptidases and wall-associated enzymes support envelope construction.
How it works
- Penicillin-binding proteins, FtsI-family transpeptidases and L,D-transpeptidase annotations identify different peptidoglycan construction activities. Lytic transglycosylase annotations identify wall-cleaving or remodeling activities.
- During envelope growth, new wall material is incorporated and peptide crosslinks are made while selected bonds in existing material are opened or reorganized. Construction and controlled cleavage must be coordinated.
- Remodeling is a branching set of substrate-specific reactions, not a chain in which every listed enzyme acts on the same molecule. Protein-specific roles in septation or elongation remain distinct.
Grouped by the atlas’s curated pathway map. The table order is not a proven reaction order.
Its proteins
| Protein | EC | Reaction (UniProt) | Metal or cluster | Amino acids | Certainty |
|---|---|---|---|---|---|
| Invasion protein IagB | — | — | — | 184 | System only |
| Penicillin binding protein 2 | — | — | — | 578 | Step named |
| Probable endolytic peptidoglycan transglycosylase RlpA | 4.2.2.- | — | — | 226 | Step named |
| Penicillin binding protein 2 | — | — | — | 595 | Step named |
| L,D-TPase catalytic domain-containing protein | — | — | — | 397 | System only |
| Penicillin-binding protein 1A | 2.4.99.28; 3.4.16.4 | [GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)](n)-di-trans,octa-cis-undecaprenyl diphosphate + beta-D-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-di-trans,octa-cis-undecaprenyl diphosphate = [GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)](n+1)-di-trans,octa-cis-undecaprenyl diphosphate + di-trans,octa-cis-undecaprenyl diphosphate + H(+) | — | 726 | Step named |
| Endolytic murein transglycosylase | 4.2.2.29 | a peptidoglycan chain = a peptidoglycan chain with N-acetyl-1,6-anhydromuramyl-[peptide] at the reducing end + a peptidoglycan chain with N-acetylglucosamine at the non-reducing end. | — | 326 | Step named |
Origins
How could a cell wall be built and reshaped before these enzymes existed?
None of the books searched discusses a prebiotic origin of the bacterial cell wall.
The wall must be enlarged while the cell grows and cut and rebuilt where it divides, without ever opening a hole that would let the cell burst. Five proteins in this pathway cross-link and remodel it.
The wider question for this part of the cell: origins for dividing into two cells.
Sources
- Atlas pathway grouping from the VF5 reference-genome system map (Deckert et al. 1998; Braakman & Smith 2014)
Other pathways in this group: Peptidoglycan precursors · Division scaffold · Envelope assembly and division · Division-associated membrane parts · Peptidoglycan biosynthesis · Not yet placed in a pathway