Structure and Activity of PA5508, a Hexameric Glutamine Synthetase Homologue.Ladner, J.E., Atanasova, V., Dolezelova, Z., Parsons, J.F.
(2012) Biochemistry 51: 10121-10123
- PubMed: 23234431
- DOI: https://doi.org/10.1021/bi3014856
- Primary Citation of Related Structures:
- PubMed Abstract:
The structure of PA5508 from Pseudomonas aeruginosa, a glutamine synthetase (GS) homologue, has been determined at 2.5 Å. Surprisingly, PA5508 forms single hexameric rings rather than the stacked double rings that are characteristic of GS. The C-terminal helical thong motif that links GS rings is present in PA5508; however, it is folded back toward the core of its own polypeptide, preventing it from interacting with a second ring. Interestingly, PA5508 displays a clear preference for aromatic amine substrates. Unique aspects of the structure illustrate how the enzyme is able to catalyze reactions involving bulky amines rather than ammonia.
Institute for Bioscience and Biotechnology Research, University of Maryland, MD, USA.