EC Number   |
General Information |
Reference |
|---|
   2.3.2.16 | metabolism |
kinase Stk and phosphatase Stp modulate cell wall synthesis and cell division at several levels. Enzyme FemB interacts with the eukaryotic-like serine/threonine kinase Stk, but is not phosphorylated by it, while the lipid II:glycine glycyltransferase FemX can be phosphorylated by the Ser/Thr kinase Stk in vitro. The cognate phosphatase Stp dephosphorylates these phosphorylation sites. Stk interacts with FemA/B and other cell wall synthesis and cell division proteins, but Stk does not phosphorylate FemA and FemB. Interaction network of Stk, Stp and FemX/A/B proteins among cell wall synthesis and cell division proteins as determined by bacterial two-hybrid analysis, overview |
-, 760162 |
| 2.3.2.16 | physiological function |
FemX catalyzes the first step in the synthesis of the pentaglycine interpeptide bridge crosslinking different glycan strands in Staphylococcus aureus. FemX uses MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala-diphosphoundecaprenyl-M-acetylglucosamine, i.e. lipid II, exclusively as acceptor for the first glycine residue. Addition of glycine residues 2, 3 and glycine residues 4, 5 is catalyzed by enzymes FemA and FemB, respectively. None of the FemABX enzymes requires the presence of one or two of the other Fem proteins for activity, rather, bridge formation is delayed in an in vitro system when all 3 enzymes are present |
705764 |
| 2.3.2.16 | physiological function |
surface protein is linked to tri- and monoglycyl cross-bridges of peptidoglycan isolated from femB and femA mutant staphylococci, respectively. No surface protein is found linked directly to the epsilon-amino group of lysyl within the cell wall of a femAX strain |
704390 |
| 2.3.2.16 | physiological function |
the bacterial cell envelope is essential for survival and pathogenicity. It forms a barrier against environmental stresses and contributes to virulence and antibiotic resistance. The cell wall of Gram-positive bacteria is composed of a multi-layered mesh of cross-linked peptidoglycan (PGN). PGN consists of chains of repeating disaccharide units comprising N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc). The lactoyl group of MurNAc is supplemented with a penta stem peptide (L-Ala-D-isoGlu-L-Lys-D-Ala-D-Ala). The staphylococcal PGN polysaccharide chains are highly cross-linked via interpeptide bridges of five glycyl residues protruding from the L-lysine of the stem-peptides4. These interpeptide bridges are synthesized by the FemX/A/B enzymes. These non-ribosomal peptidyl-transferases use glycyltRNAs to sequentially add five glycine's to the PGN-lysyl side chain of lipid II. FemX adds the first glycyl unit, FemA the second and third unit, and FemB adds the fourth and fifth glycyl unit to complete the pentaglycine-bridge. Enzyme FemB interacts with the eukaryotic-like serine/threonine kinase Stk, but is not phosphorylated by it. FemA and FemB interact with Stk and with cell wall synthesis enzymes (MurG, Pbp1, Pbp2), Mgt, LytH, RodA, FtsW and cell division proteins (DivIB, DivIC, EzrA). FemA and FemB interact with each other and also form homodimers, which is not the case for FemX. In contrast to FemX, the subsequent enzymes FemA or FemB are non-essential. The essential cell wall synthesis enzyme FemX is a target of Stk and Stp |
-, 760162 |
