Periplasmic dipeptide-binding protein: Difference between revisions

Between the two halves of the protein, buried inside the core, is a <scene name='84/842887/Tetrapeptide/2'>tetrapeptide composed of Ser-Ser-Val-Thr</scene><ref name=Alex/>.  The function of this is not as of yet fully understood.  The highly conserved residues <scene name='84/842887/Tetrapeptide2/2'>W442 and D445</scene> in the peptide-binding pocket of DppA were mutated to alanine by researchers<ref name=Alex/>. E. Coli did not yield any D445 mutant protein, suggesting it did not fold and subsequently degraded<ref name=Alex/>.  E. Coli did yield W442 mutant which, under spectroscopic analysis, appeared to bind and rapidly dissociate from heme<ref name=Alex/>.  This suggests that this residue perhaps plays a role in maintaining a specific flexibility of the DppA halves.