Download MendeleyInsights into protein adaptation to a saturated salt environment from the crystal structure of a halophilic 2Fe-2S ferredoxin.
Frolow, F., Harel, M., Sussman, J.L., Mevarech, M., Shoham, M.(1996) Nat Struct Biol 3: 452-458
- PubMed: 8612076 Search on PubMed
- DOI: https://doi.org/10.1038/nsb0596-452
- Primary Citation Related Structures:
1DOI - PubMed Abstract:
Haloarcula marismortui is an archaebacterium that flourishes in the world's saltiest body of water, the Dead Sea. The cytosol of this organism is a supersaturated salt solution in which proteins are soluble and active. The crystal structure of a 2Fe-2S ferredoxin from H. marismortui determined at 1.9 A is similar to those of plant-type 2Fe-2S ferredoxins of known structure, with two important distinctions. The entire surface of the protein is coated with acidic residues except for the vicinity of the iron-sulphur cluster, and there is an insertion of two amphipathic helices near the N-terminus. These form a separate hyperacidic domain whose postulated function to provide extra surface carboxylates for solvation. These data and the fact that bound surface water molecules have on the average 40% more hydrogen bonds than in a typical non-halophilic protein crystal structure support the notion that haloadaptation involves better water binding capacity.
- Department of Structural Biology, The Weizmann Institute of Science, Rehovot, Israel.
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