2d0s
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Crystal structure of the Cytochrome C552 from moderate thermophilic bacterium, hydrogenophilus thermoluteolus
OverviewOverview
We have studied the structure-thermostability relationship using, cytochromes c from mesophilic and thermophilic bacteria; Pseudomonas, aeruginosa (PAc(551)) growing at 37 degrees C and Hydrogenobacter, thermophilus (HTc(552)) at 72 degrees C and showed that only five residues, primarily differentiate their stabilities. For a more comprehensive study, we found Hydrogenophilus thermoluteolus (Pseudomonas hydrogenothermophila), growing at 52 degrees C and showed the moderate stability of the, cytochrome c from this bacterium (PHc(552)). To explore the stabilization, mechanisms, the crystal structure of PHc(552) was determined by X-ray, analysis. The solution structure of HTc(552) elucidated previously by NMR, was refined using distributed computational implementation. Furthermore, the recently reported crystal structure of HTc(552) has become available, [Travaglini-Allocatelli, C. et al. (2005) J. Biol. Chem. 280, 25729-25734]. When the structures of these three cytochromes c were, combined, this revealed that the five residues, corresponding to those, mentioned above, determine the difference of stabilities among them as, well. These facts suggested the stabilization mechanisms as follows: (1), improved van der Waals interactions by packing optimization at the, N-terminal helix, (2) attractive electrostatic interactions with the heme, propionate group, and (3) favorable van der Waals interaction with the, heme. This comparative study, by supplementing the structural information, of PHc(552) with its complementary feature, demonstrates that just a small, number of amino acid residues determine the overall molecular stability by, means of additivity of the effects of their substitutions. It is, interesting that, in naturally occurring proteins, these adaptation, strategies are accommodated by these bacteria to survive in the wide range, of thermal conditions.
About this StructureAbout this Structure
2D0S is a Single protein structure of sequence from Hydrogenophilus thermoluteolus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Structure of cytochrome c552 from a moderate thermophilic bacterium, Hydrogenophilus thermoluteolus: comparative study on the thermostability of cytochrome c., Nakamura S, Ichiki S, Takashima H, Uchiyama S, Hasegawa J, Kobayashi Y, Sambongi Y, Ohkubo T, Biochemistry. 2006 May 16;45(19):6115-23. PMID:16681384
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