X-ray structure of the signal transduction protein from Escherichia coli at 1.9 Å

Abstract

The structure of the bacterial signal transduction protein

Direct Interaction of the NifL Regulatory Protein with the GlnK Signal Transducer Enables the Azotobacter vinelandiiNifL-NifA Regulatory System to Respond to Conditions Replete for Nitrogen

“…X-ray crystallographic analysis of the homotrimeric PII and GlnK proteins from E. coli reveals a similar structural core, although the conformation of the apical T-loop can alter significantly (43)(44)(45). The T-loop region of Ec PII is necessary for interaction with ATase, UTase, and NtrB and includes Tyr-51, the site of uridylylation (31,33).…”

The Story of Glutamine Synthetase Regulation

“…This led to further studies by Mangum et al on the role of P II in GS regulation (26) and studies by Garcia and Rhee (27) showing that the uridylylation and deuridylylation of P II is catalyzed by the same uridylyltransferase (UTase). Subsequently, Adler et al (28) obtained a homogeneous preparation of P II and showed that it is a protein of about M r 44,000, which was later shown by other workers to be a trimer (29). In continuing studies, Adler and Purich showed that uridylylation of P II involves covalent attachment of a uridylyl group from UTP to a particular tyrosine residue in each subunit (Reaction 3, where n ϭ 1-3) and that deuridylylation of the uridylylated P II is a hydrolytic process (Reaction 4).…”

Nitrogen Fixation In Methanogens: The Archaeal Perspective

“…Arabic numerals indicate gene designations relative to whole genome analyses (9,14). The predicted T-loop is indicated (39,40). * indicates the tyrosine reside which is the conserved site of uridylylation in Bacteria.…”