4WPG

Group A Streptococcus GacA is an essential dTDP-4-dehydrorhamnose reductase (RmlD)

Summary for 4WPG

• Entry DOI: 10.2210/pdb4wpg/pdb
• Descriptor: dTDP-4-dehydrorhamnose reductase, (4S)-2-METHYL-2,4-PENTANEDIOL, (4R)-2-METHYLPENTANE-2,4-DIOL, ... (5 entities in total)
• Functional Keywords: rmld, dtdp-4-dehydrorhamnose reductase, oxidoreductase
• Biological source: Streptococcus pyogenes
• Total number of polymer chains: 1
• Total formula weight: 32866.85

Authors

van der Beek, S.L.,Le Breton, Y.,Ferenbach, A.T.,van Aalten, D.M.F.,Navratilova, I.,McIver, K.,van Sorge, N.M.,Dorfmueller, H.C. (deposition date: 2014-10-18, release date: 2015-09-09, Last modification date: 2024-05-08)

Primary citation

van der Beek, S.L.,Le Breton, Y.,Ferenbach, A.T.,Chapman, R.N.,van Aalten, D.M.,Navratilova, I.,Boons, G.J.,McIver, K.S.,van Sorge, N.M.,Dorfmueller, H.C.
GacA is essential for Group A Streptococcus and defines a new class of monomeric dTDP-4-dehydrorhamnose reductases (RmlD).
Mol.Microbiol., 98:946-962, 2015

PubMed Abstract: The sugar nucleotide dTDP-L-rhamnose is critical for the biosynthesis of the Group A Carbohydrate, the molecular signature and virulence determinant of the human pathogen Group A Streptococcus (GAS). The final step of the four-step dTDP-L-rhamnose biosynthesis pathway is catalyzed by dTDP-4-dehydrorhamnose reductases (RmlD). RmlD from the Gram-negative bacterium Salmonella is the only structurally characterized family member and requires metal-dependent homo-dimerization for enzymatic activity. Using a biochemical and structural biology approach, we demonstrate that the only RmlD homologue from GAS, previously renamed GacA, functions in a novel monomeric manner. Sequence analysis of 213 Gram-negative and Gram-positive RmlD homologues predicts that enzymes from all Gram-positive species lack a dimerization motif and function as monomers. The enzymatic function of GacA was confirmed through heterologous expression of gacA in a S. mutans rmlD knockout, which restored attenuated growth and aberrant cell division. Finally, analysis of a saturated mutant GAS library using Tn-sequencing and generation of a conditional-expression mutant identified gacA as an essential gene for GAS. In conclusion, GacA is an essential monomeric enzyme in GAS and representative of monomeric RmlD enzymes in Gram-positive bacteria and a subset of Gram-negative bacteria. These results will help future screens for novel inhibitors of dTDP-L-rhamnose biosynthesis.

PubMed: 26278404
DOI: 10.1111/mmi.13169

Experimental method

X-RAY DIFFRACTION (1.1 Å)