NMR structure of the C-terminal domain of SecA in the free state.
SecA is an integral component of the prokaryotic Sec preprotein secretory translocase system. We report here the solution NMR structure of a fragment corresponding to the C-terminal domain of Escherichia coli SecA. In the presence of Zn2+, the fragment adopts a shortened version of the classic betabetaalpha zinc finger fold. The isolated C-terminal domain shows substantial differences from the X-ray structure of a homologous SecA domain bound to the chaperone-like cofactor SecB. The differences between the structures of the free and bound forms suggest that binding to SecB causes a perturbation of the C-terminal domain's intrinsically favored betabetaalpha fold.
Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, U-3125, Storrs, CT 06269-3125, USA.
William M
WM
Matousek
Andrei T
AT
Alexandrescu
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017510:Protein Folding; D017433:Protein Structure, Secondary; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D016415:Sequence Alignment; D015032:Zinc / Q000737:chemistry; D016335:Zinc Fingers
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins; D015032:Zinc