ISSN:
1572-8854
Keywords:
protein nucleic acid interaction
;
inosine 5′-monophosphate-L-glutamine complex
;
hydration economy
;
water-mediated recognition
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract The crystal structure of a unidecahydrated co-complex between two Inosine 5′-monophosphate (IMP) and one L-glutamine has been determined at atomic resolution by X-ray crystallographic methods. The crystal belongs to the monoclinic space group P21 with cell dimensions a = 8.690(2), b = 21.900(3), c = 12.370(1) Å, and β = 110.59(3)°. This structure reveals the recognition mechanism of glutamine to the nucleotide through direct and water-mediated hydrogen bonds. The phosphate oxygen (O23) seems to prefer the nonspecific interaction with the functional sites of glutamine (NA· · ·O23 = 2.672, OH· · ·O23 = 3.063, OE· · ·O23 = 3.104 Å), whereas the bases prefer specific (N23· · ·O = 2.874 Å) bindings. But here no specific interaction has been observed at N17 and N27, which were observed in serine—IMP complex. However, the solvent mediated N17· · ·OW3· · ·N27 hydrogen bonds for stabilization of the stacked purine bases have been observed as in other aminoacid-nucleotide cocrystals. The striking habit of glutamine to occupy the nearly same region of the nucleotide cocrystal as was found in the serine—IMP complex through substantial replacement of free and bound water molecules, shows certainly the cooperative hydrogen bonding economy of water molecules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009536500377
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