Molecular modeling annual

, Volume 8, Issue 2, pp 58–64 | Cite as

Homology modeling reveals the structural background of the striking difference in thermal stability between two related [NiFe]hydrogenases

  • András Szilágyi
  • Kornél L. Kovács
  • Gábor Rákhely
  • Péter Závodszky
Original Paper

Abstract.

Hydrogenases are redox metalloenzymes in bacteria that catalyze the uptake or production of molecular hydrogen. Two homologous nickel–iron hydrogenases, HupSL and HydSL from the photosynthetic purple sulfur bacterium Thiocapsa roseopersicina, differ substantially in their thermal stabilities despite the high sequence similarity between them. The optimum temperature of HydSL activity is estimated to be at least 50 °C higher than that of HupSL. In this work, homology models of both proteins were constructed and analyzed for a number of structural properties. The comparison of the models reveals that the higher stability of HydSL can be attributed to increased inter-subunit electrostatic interactions: the homology models reliably predict that HydSL contains at least five more inter-subunit ion pairs than HupSL. The subunit interface of HydSL is more polar than that of HupSL, and it contains a few extra inter-subunit hydrogen bonds. A more optimized cavity system and amino acid replacements resulting in increased conformational rigidity may also contribute to the higher stability of HydSL. The results are in accord with the general observation that with increasing temperature, the role of electrostatic interactions in protein stability increases. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00894-001-0071-8.

Keywords

Thiocapsa roseopersicina– Hydrogenase – Metalloenzymes – Homology modeling – Protein stability 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Supplementary material

In order to view the Electronic Supplementary Material, please download the following zip-file

supp_mat.zip (237 kb)
supp_mat.zip

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • András Szilágyi
    • 1
  • Kornél L. Kovács
    • 2
  • Gábor Rákhely
    • 2
  • Péter Závodszky
    • 1
  1. 1.Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Karolina út 29, H-1113 Budapest, Hungary E-mail: szia@enzim.hu Phone: +36 1 466 5633 Fax: +36 1 466 5465HU
  2. 2.Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, HungaryHU

Personalised recommendations