2bmd: Difference between revisions

The Ras-related human GTPase Rab4a is involved in the regulation of, endocytosis through the sorting and recycling of early endosomes. Towards, further insight, we have determined the three-dimensional crystal, structure of human Rab4a in its GppNHp-bound state to 1.6 Angstroms, resolution and in its GDP-bound state to 1.8 Angstroms resolution, respectively. Despite the similarity of the overall structure with other, Rab proteins, Rab4a displays significant differences. The structures are, discussed with respect to the recently determined structure of human Rab5a, and its complex with the Rab5-binding domain of the bivalent effector, Rabaptin-5. The Rab4 specific residue His39 modulates the nucleotide, binding pocket giving rise to a reduced rate for nucleotide hydrolysis and, exchange. In comparison to Rab5, Rab4a has a different GDP-bound, conformation within switch 1 region and displays shifts in position and, orientation of the hydrophobic triad. The observed differences at the, S2-L3-S3 region represent a new example of structural plasticity among Rab, proteins and may provide a structural basis to understand the differential, binding of similar effector proteins.

2BMD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with GDP and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Small_monomeric_GTPase Small monomeric GTPase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.5.2 3.6.5.2] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BMD OCA].  

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