PROSITE documentation PDOC51426 [for PROSITE entry PS51426]

ABL domain profile

The Rcs signaling pathway controls a variety of physiological functions like capsule synthesis, cell division or motility in prokaryotes. The Rcs regulatory pathway is a complex modification of the standard bacterial two-component signaling systems. The Rcs regulatory cascade, involving a multi-step phosphorelay between the two membrane bound hybrid sensor kinases RcsC and RcsD and the global regulator RcsB, is, up to now, one of the most complicated regulatory systems in bacteria. This signal transfer is mediated by a RcsC/RcsD/RcsB phosphorelay cascade involving conserved integrated phosphate shuttle domains [1].

The ABL (α/β/Loop) domain is found between the histidine kinase domain (see <PDOC50109>) and the response regulatory domain (see <PDOC50110>) of all RcsC sequences of all enterobacteria sequenced so far. The central element of the ABL domain structure is a five-stranded parallel β-sheet. Packed against one side of this sheet are two α helices while the remaining connection between the individual β-strands is provided by three loops, all located on the opposite side of the β-sheet (see <PDB:2AYY>). It shows a structural similarity to the response regulatory domain and contains a conserved aspartate residue in a location that corresponds to the active site in the response regulatory domain. However the ABL domain does not appear to play a direct role in the phosphoryl transfer [1].

The profile we developed covers the entire ABL domain.