1OKK

HOMO-HETERODIMERIC COMPLEX OF THE SRP GTPASES

Summary for 1OKK

• Entry DOI: 10.2210/pdb1okk/pdb
• Related: 1FFH 1JPJ 1JPN 1LS1 1NG1 1O87 1RJ9 2FFH 2NG1 3NG1
• Descriptor: SIGNAL RECOGNITION PARTICLE PROTEIN, CELL DIVISION PROTEIN FTSY, PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER, ... (8 entities in total)
• Functional Keywords: cell cycle, signal recognition-complex, srp, ffh, ftsy, gtpase, membrane targeting, signal sequence recognition
• Biological source: THERMUS AQUATICUS; More
• Cellular location: Cell inner membrane; Peripheral membrane protein (By similarity): P83749
• Total number of polymer chains: 2
• Total formula weight: 67928.88

Authors

Focia, P.J.,Freymann, D.M. (deposition date: 2003-07-26, release date: 2004-01-19, Last modification date: 2023-12-13)

Primary citation

Focia, P.J.,Shepotinovskaya, I.V.,Seidler, J.A.,Freymann, D.M.
Heterodimeric Gtpase Core of the Srp Targeting Complex
Science, 303:373-, 2004

PubMed Abstract: Two structurally homologous guanosine triphosphatase (GTPase) domains interact directly during signal recognition particle (SRP)-mediated cotranslational targeting of proteins to the membrane. The 2.05 angstrom structure of a complex of the NG GTPase domains of Ffh and FtsY reveals a remarkably symmetric heterodimer sequestering a composite active site that contains two bound nucleotides. The structure explains the coordinate activation of the two GTPases. Conformational changes coupled to formation of their extensive interface may function allosterically to signal formation of the targeting complex to the signal-sequence binding site and the translocon. We propose that the complex represents a molecular "latch" and that its disengagement is regulated by completion of assembly of the GTPase active site.

PubMed: 14726591
DOI: 10.1126/SCIENCE.1090827

Experimental method

X-RAY DIFFRACTION (2.05 Å)