Regulation of the catalytic activity of by-kinases

Abstract

BY-kinases (for Bacterial tYrosine kinase) comprise a unique family of protein tyrosine kinases that highly conserved in bacteria but that have no eukaryotic counterparts. A unique feature thatsets the BY-kinases apart from eukaryotic protein kinases is their deployment of a P-loop NTPase structural scaffold, noted by the presence of nucleotide-binding Walker-A and B motifs, in lieu of the dual-lobed fold characteristic of eukaryotic tyrosine kinases. Unlike many eukaryotic protein kinases, the BY-kinases cannot be classified as active or inactive based on the quantitative phosphorylation state of any particular residue or residues.