1FFH
N AND GTPASE DOMAINS OF THE SIGNAL SEQUENCE RECOGNITION PROTEIN FFH FROM THERMUS AQUATICUS
Summary for 1FFH
| Entry DOI | 10.2210/pdb1ffh/pdb |
| Descriptor | FFH, MAGNESIUM ION (3 entities in total) |
| Functional Keywords | ffh, srp, gtpase, signal recognition particle, ribonucleoprotein |
| Biological source | Thermus aquaticus |
| Total number of polymer chains | 1 |
| Total formula weight | 32280.56 |
| Authors | Freymann, D.M.,Keenan, R.J.,Stroud, R.M.,Walter, P. (deposition date: 1996-12-30, release date: 1997-12-31, Last modification date: 2024-02-07) |
| Primary citation | Freymann, D.M.,Keenan, R.J.,Stroud, R.M.,Walter, P. Structure of the conserved GTPase domain of the signal recognition particle. Nature, 385:361-364, 1997 Cited by PubMed Abstract: The signal-recognition particle (SRP) and its receptor (SR) function in the co-translational targeting of nascent protein-ribosome complexes to the membrane translocation apparatus. The SRP protein subunit (termed Ffh in bacteria) that recognizes the signal sequence of nascent polypeptides is a GTPase, as is the SR-alpha subunit (termed FtsY). Ffh and FtsY interact directly, each stimulating the GTP hydrolysis activity of the other. The sequence of Ffh suggests three domains: an amino-terminal N domain of unknown function, a central GTPase G domain, and a methionine-rich M domain that binds both SRP RNA and signal peptides. Sequence conservation suggests that structurally similar N and G domains are present in FtsY. Here we report the structure of the nucleotide-free form of the NG fragment of Ffh. Consistent with a role for apo Ffh in protein targeting, the side chains of the empty active-site pocket form a tight network of interactions which may stabilize the nucleotide-free protein. The structural relationship between the two domains suggests that the N domain senses or controls the nucleotide occupancy of the GTPase domain. A structural subdomain unique to these evolutionarily conserved GTPases constitutes them as a distinct subfamily in the GTPase superfamily. PubMed: 9002524DOI: 10.1038/385361a0 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.05 Å) |
Structure validation
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