1gtf: Difference between revisions

The trp RNA-binding attenuation protein (TRAP) regulates expression of the, tryptophan biosynthetic genes in bacilli by binding to the leader region, of the nascent trp operon mRNA. When activated by binding tryptophan, the, 11-subunit circular TRAP molecule binds to a target sequence consisting of, 11 (G/U)AG repeats, separated by two or three variable 'spacer', nucleotides. Reported here are two crystal structures of TRAP bound to, RNAs containing 11 GAG repeats separated by UU and CC spacer nucleotides, determined at 1.75 and 2.50 A resolution, respectively. These show the, spacer regions of the RNA molecules to be highly flexible, making no, direct hydrogen-bonding contacts with the protein. Comparison of these, structures with the previous structure of TRAP bound to (GAGAU)(10)GAG, RNA, in which the spacer nucleotides stack with each other close to the, protein surface, shows that the RNA can adopt different conformations, depending on the sequence of the spacer regions. This gives insight into, the structural basis of the specificity of TRAP and into the mechanism of, binding.

1GTF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus] with TRP as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Sites: AC1, AC2, AC3, AC4, AC5, AC6, AC7, AC8, AC9, BC1, BC2, BC3, BC4, BC5, BC6, BC7, BC8, BC9, CC1, CC2, CC3 and CC4. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1GTF OCA].  

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