GlnK, a PII-homologue: structure reveals ATP binding site and indicates how the T-loops may be involved in molecular recognition.
Y Xu, E Cheah, PD Carr, WC van Heeswijk, HV Westerhoff, SG Vasudevan, DL Ollis
J Mol Biol | Published : 1998
GlnK is a recently discovered homologue of the PII signal protein, an indicator of the nitrogen status of bacteria. PII occupies a central position in the dual cascade that regulates the activity of glutamine synthetase and the transcription of its gene. The complete role of Escherichia coli GlnK is yet to be determined, but already it is known that GlnK behaves like PII and can substitute for PII under some circumstances thereby adding to the subtleties of nitrogen regulation. There are also indications that the roles of the two proteins differ; the expression of PII is constitutive while that of GlnK is linked to the level of nitrogen in the cell. The discovery of GlnK begs the question of..View full abstract