The Staphylococcal Transferrin-Binding Protein Is a Cell Wall Glyceraldehyde-3-Phosphate Dehydrogenase

Abstract

Staphylococcus aureus and Staphylococcus epidermidis possess a 42-kDa cell wall transferrin-binding protein (Tpn) which is involved in the acquisition of transferrin-bound iron. To characterize this protein further, cell wall fractions were subjected to two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis blotted, and the N-terminus of Tpn was sequenced. Comparison of the first 20 amino acid residues of Tpn with the protein databases revealed a high degree of homology to the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Analysis of staphylococcal cell wall fractions for GAPDH activity confirmed the presence of a functional enzyme which, like Tpn, is regulated by the availability of iron in the growth medium. To determine whether Tpn is responsible for this GAPDH activity, it was affinity purified with NAD+ agarose. BothS. epidermidis and S. aureus Tpn catalyzed the conversion of glyceraldehyde-3-phosphate to 1,3-diphosphoglycerate. In contrast, Staphylococcus saprophyticus, which lacks a Tpn, has no cell wall-associated GAPDH activity. Native polyacrylamide gel electrophoresis of the affinity-purified Tpn revealed that it was present in the cell wall as a tetramer, consistent with the structures of all known cytoplasmic GAPDHs. Furthermore, the affinity-purified Tpn retained its ability to bind human transferrin both in its native tetrameric and SDS-denatured monomeric forms. Apart from interacting with human transferrin, Tpn, in common with the group A streptococcal cell wall GAPDH, binds human plasmin. Tpn-bound plasmin is enzymatically active and therefore may contribute to the ability of staphylococci to penetrate tissues during infections. These studies demonstrate that the staphylococcal transferrin receptor protein, Tpn, is a multifunctional cell wall GAPDH.

Structural insights into RNA recognition properties of glyceraldehyde‐3‐phosphate dehydrogenase 3 from Saccharomyces cerevisiae

“…Enzymatic activity studies of recombinant S. cerevisiae GAPDH3 showed that the apparent K NAD is 686 lM (Fig. 1A), which is close to the value reported for homologous GAPDHs (19). This result indicated that the recombinant GAPDH3 was correctly folded and had biological activity.…”

The moonlighting protein fructose-1, 6-bisphosphate aldolase of Neisseria meningitidis: surface localization and role in host cell adhesion

“…In Mycoplasma genitalium, surface-associated GAPDH was shown to be important for adhesion to human mucin (Alvarez et al, 2003). In Streptococcus pyogenes and Candida albicans surface-associated GAPDH was shown to bind to fibronectin (Pancholi and Fischetti, 1992;Gozalbo et al, 1998) and in Staphylococcus aureus the cell wall transferrin-binding protein was found to be GAPDH (Modun and Williams, 1999). GAPDH was also reported to be a virulence-associated immunomodulatory protein in Streptococcus agalactiae (Madureira et al, 2007).…”

Proposal of screening method for intestinal mucus adhesive lactobacilli using the enzymatic activity of glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH)

“…(2003) reported enzymatically active GAPDH is capable of binding to cytoskeletal and extra‐cellular matrix proteins and is expressed on the surface of group B Streptococcus . Surface‐localized GAPDH of Staphylococcus aureus and Staphylococcus epidermidis bind transferrin (Modun & Williams 1999), whereas the GAPDH of Candida albicans binds fibronectin and laminin (Gozalbo et al . 1998).…”