Structure of SO2946 orphan from Shewanella oneidensis shows “jelly-roll” fold with carbohydrate-binding module
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The crystal structure of the uncharacterized protein SO2946 from Shewanella oneidensis MR-1 was determined with single-wavelength anomalous diffraction (SAD) and refined to 2.0 Å resolution. The SO2946 protein consists of a short helical N-terminal domain and a large C-terminal domain with the “jelly-roll” topology. The protein assembles into a propeller consisting of three C-terminal blades arranged around a central core formed by the N-terminal domains. The function of SO2946 could not be inferred from the sequence since the protein represents an orphan with no sequence homologs, but the protein’s structure bears a fold similar to that of proteins containing carbohydrate-binding modules. Features such as fold conservation, the presence of a conserved groove and a metal binding region are indicative that SO2946 may be an enzyme and could be involved in binding carbohydrate molecules.
KeywordsJelly-roll topology Carbohydrate-binding modules Orphan protein Magnesium binding SAD phasing Singleton
- 15.Bailey (1994) The CCP4 suite: programs for protein crystallography. Acta Crystallogr D Biol Crystallogr 50:760–763Google Scholar
- 26.Kundhavai Natchiar S, Arockia Jeyaprakash A, Ramya TN, Thomas CJ, Suguna K, Surolia A, Vijayan M (2004) Structural plasticity of peanut lectin: an X-ray analysis involving variation in pH, ligand binding and crystal structure. Acta Crystallogr D Biol Crystallogr 60(pt 2):211–219PubMedCrossRefGoogle Scholar
- 30.Carvalho AL, Goyal A, Prates JA, Bolam DN, Gilbert HJ, Pires VM, Ferreira LM, Planas A, Romao MJ, Fontes CM (2004) The family 11 carbohydrate-binding module of Clostridium thermocellum Lic26A-Cel5E accommodates beta-1, 4- and beta-1, 3-1, 4-mixed linked glucans at a single binding site. J Biol Chem 279:34785–34793PubMedCrossRefGoogle Scholar