3fou | pdb_00003fou

Low pH structure of the Rieske protein from Thermus thermophilus at 2.1 A

spinqualitylabelsall models 3fou, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3fou is a 2 chain structure with sequence from Thet8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ACT, CA, FES, PR Related: 1nyk Gene: TTHA1931 (THET8) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The Rieske protein from Thermus thermophilus (TtRp) and a truncated version of the protein (truncTtRp), produced to achieve a low-pH crystallization condition, have been characterized using UV-visible and circular dichroism spectroscopies. TtRp and truncTtRp undergo a change in the UV-visible spectra with increasing pH. The LMCT band at 458 nm shifts to 436 nm and increases in intensity. The increase at 436 nm versus pH can be fit using the sum of two Henderson-Hasselbalch equations, yielding two pK(a) values for the oxidized protein. For TtRp, pK(ox1) = 7.48 +/- 0.12 and pK(ox2) = 10.07 +/- 0.17. For truncTtRp, pK(ox1) = 7.87 +/- 0.17 and pK(ox2) = 9.84 +/- 0.42. The shift to shorter wavelength and the increase in intensity for the LMCT band with increasing pH are consistent with deprotonation of the histidine ligands. A pH titration of truncTtRp monitored by circular dichroism also showed pH-dependent changes at 315 and 340 nm. At 340 nm, the fit gives pK(ox1) = 7.14 +/- 0.26 and pK(ox2) = 9.32 +/- 0.36. The change at 315 nm is best fit for a single deprotonation event, giving pK(ox1) = 7.82 +/- 0.10. The lower wavelength region of the CD spectra was unaffected by pH, indicating that the overall fold of the protein remains unchanged, which is consistent with crystallographic results of truncTtRp. The structure of truncTtRp crystallized at pH 6.2 is very similar to TtRp at pH 8.5 and contains only subtle changes localized at the [2Fe-2S] cluster. These titration and structural results further elucidate the histidine ligand characteristics and are consistent with important roles for these amino acids. Effects of pH on the Rieske protein from Thermus thermophilus: a spectroscopic and structural analysis.,Konkle ME, Muellner SK, Schwander AL, Dicus MM, Pokhrel R, Britt RD, Taylor AB, Hunsicker-Wang LM Biochemistry. 2009 Oct 20;48(41):9848-57. PMID:19772300 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA