Structure ofStreptococcus agalactiaeglyceraldehyde-3-phosphate dehydrogenase holoenzyme reveals a novel surface

Abstract

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a conserved cytosolic enzyme, which plays a key role in glycolysis. GAPDH catalyzes the oxidative phosphorylation of D-glyceraldehyde 3-phosphate using NAD or NADP as a cofactor. In addition, GAPDH localized on the surface of some bacteria is thought to be involved in macromolecular interactions and bacterial pathogenesis. GAPDH on the surface of group B streptococcus (GBS) enhances bacterial virulence and is a potential vaccine candidate. Here, the crystal structure of GBS GAPDH from Streptococcus agalactiae in complex with NAD is reported at 2.46 Å resolution. Although the overall structure of GBS GAPDH is very similar to those of other GAPDHs, the crystal structure reveals a significant difference in the area spanning residues 294-307, which appears to be more acidic. The amino-acid sequence of this region of GBS GAPDH is also distinct compared with other GAPDHs. This region therefore may be of interest as an immunogen for vaccine development.

Crystal Structures of Group B Streptococcus Glyceraldehyde-3-Phosphate Dehydrogenase: Apo-Form, Binary and Ternary Complexes

“…In the crystal structures the subunits (A, B, C and D) in the asymmetric unit are related by 222 non-crystallographic (NCS) symmetry (Fig 1). The overall structure and topology of GBS GAPDH are similar to other GAPDHs [10–21]. Each GAPDH subunit is composed of two domains, and consists of 13 helices and 2 β-sheets of 9 and 8 strands.…”

“…It also represents the area of most divergent amino acid sequence in GAPDHs. We have previously discussed the structural characteristic of this region [10]. In region 1, which is comprised of nine residues, hGAPDH and GBS GAPDH share only one identical residue (Gly63 in GBS) and two conservative substitutions (S5 Table).…”

“…Wild type and mutant GBS GAPDH were purified as previously described [10]. The C152S mutant was generated using a standard protocol and purified as described for the wild type protein [10].…”

“…The C152S mutant was generated using a standard protocol and purified as described for the wild type protein [10]. …”

“…Previously, we determined the crystal structure of GBS GAPDH in the holo-form at 2.46 Å resolution. Interestingly, this structure revealed a novel surface area, which is not present in hGAPDH [10]. Although the functional implication of this distinct feature is not known at this time, this finding underscored the need for a detailed analysis of the GBS GAPDH structure.…”