ISSN:
1399-0047
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
The signal recognition particle (SRP) of bacteria consists of only one protein, known as Ffh or the SRP54 homologue, which forms a complex with 4.5S RNA. It also binds to signal peptides and contains a GTPase which displays interesting differences to Ras GTPases. The conserved NG-domain of Ffh from the archaebacterium Acidianus ambivalens was cloned and overexpressed with a C-terminal His tag in Escherichia coli. Crystallization experiments of the native protein as well as of the Thr112Ala mutant, which is deficient in GTP hydrolysis, resulted in crystals suitable for X-ray diffraction. The crystals belong to the orthorhombic space group C2221, with unit-cell parameters a = 64.5, b = 128.3, c = 72.0 Å. At cryogenic temperatures, the crystals diffracted to a resolution limit of 2.8 Å using a rotating-anode generator and contain one molecule per asymmetric unit. A native data set has been collected using synchrotron radiation to around 2.0 Å resolution. Selenomethionine protein was produced; its crystals diffract in-house to about 2.8 Å resolution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0907444999011348
