6H5E

Crystal Structure of the GatD/MurT Enzyme Complex from Staphylococcus aureus with bound AMPPNP

Summary for 6H5E

• Entry DOI: 10.2210/pdb6h5e/pdb
• Related: 6GS2
• Descriptor: SA1707 protein, DUF1727 domain-containing protein, ZINC ION, ... (9 entities in total)
• Functional Keywords: cell wall biosynthesis, peptidoglycan, antibiotic resistance, biosynthetic protein
• Biological source: Staphylococcus aureus; More
• Total number of polymer chains: 4
• Total formula weight: 157672.93

Authors

Noeldeke, E.R.,Niemann, V.,Stoerk, E.,Stehle, T. (deposition date: 2018-07-24, release date: 2018-09-05, Last modification date: 2024-01-17)

Primary citation

Noldeke, E.R.,Muckenfuss, L.M.,Niemann, V.,Muller, A.,Stork, E.,Zocher, G.,Schneider, T.,Stehle, T.
Structural basis of cell wall peptidoglycan amidation by the GatD/MurT complex of Staphylococcus aureus.
Sci Rep, 8:12953-12953, 2018

PubMed Abstract: The peptidoglycan of Staphylococcus aureus is highly amidated. Amidation of α-D-isoglutamic acid in position 2 of the stem peptide plays a decisive role in the polymerization of cell wall building blocks. S. aureus mutants with a reduced degree of amidation are less viable and show increased susceptibility to methicillin, indicating that targeting the amidation reaction could be a useful strategy to combat this pathogen. The enzyme complex that catalyzes the formation of α-D-isoglutamine in the Lipid II stem peptide was identified recently and shown to consist of two subunits, the glutamine amidotransferase-like protein GatD and the Mur ligase homolog MurT. We have solved the crystal structure of the GatD/MurT complex at high resolution, revealing an open, boomerang-shaped conformation in which GatD is docked onto one end of MurT. Putative active site residues cluster at the interface between GatD and MurT and are contributed by both proteins, thus explaining the requirement for the assembled complex to carry out the reaction. Site-directed mutagenesis experiments confirm the validity of the observed interactions. Small-angle X-ray scattering data show that the complex has a similar conformation in solution, although some movement at domain interfaces can occur, allowing the two proteins to approach each other during catalysis. Several other Gram-positive pathogens, including Streptococcus pneumoniae, Clostridium perfringens and Mycobacterium tuberculosis have homologous enzyme complexes. Combined with established biochemical assays, the structure of the GatD/MurT complex provides a solid basis for inhibitor screening in S. aureus and other pathogens.

PubMed: 30154570
DOI: 10.1038/s41598-018-31098-x

Experimental method

X-RAY DIFFRACTION (2.139 Å)