2e1p
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Crystal structure of pro-Tk-subtilisin
OverviewOverview
The crystal structure of an active site mutant of pro-Tk-subtilisin, (pro-S324A) from the hyperthermophilic archaeon Thermococcus kodakaraensis, was determined at 2.3 A resolution. The overall structure of this protein, is similar to those of bacterial subtilisin-propeptide complexes, except, that the peptide bond linking the propeptide and mature domain contacts, with the active site, and the mature domain contains six Ca2+ binding, sites. The Ca-1 site is conserved in bacterial subtilisins but is formed, prior to autoprocessing, unlike the corresponding sites of bacterial, subtilisins. All other Ca2+-binding sites are unique in the pro-S324A, structure and are located at the surface loops. Four of them apparently, contribute to the stability of the central alphabetaalpha substructure of, the mature domain. The CD spectra, 1-anilino-8-naphthalenesulfonic acid, fluorescence spectra, and sensitivities to chymotryptic digestion of this, protein indicate that the conformation of pro-S324A is changed from an, unstable molten globule-like structure to a stable native one upon Ca2+, binding. Another active site mutant, pro-S324C, was shown to be, autoprocessed to form a propeptide-mature domain complex in the presence, of Ca2+. The CD spectra of this protein indicate that the structure of, pro-S324C is changed upon Ca2+ binding like pro-S324A but is not seriously, changed upon subsequent autoprocessing. These results suggest that the, maturation process of Tk-subtilisin is different from that of bacterial, subtilisins in terms of the requirement of Ca2+ for folding of the mature, domain and completion of the folding process prior to autoprocessing.
About this StructureAbout this Structure
2E1P is a Single protein structure of sequence from Thermococcus kodakarensis with CA as ligand. Active as Subtilisin, with EC number 3.4.21.62 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of unautoprocessed precursor of subtilisin from a hyperthermophilic archaeon: evidence for Ca2+-induced folding., Tanaka S, Saito K, Chon H, Matsumura H, Koga Y, Takano K, Kanaya S, J Biol Chem. 2007 Mar 16;282(11):8246-55. Epub 2007 Jan 19. PMID:17237225
Page seeded by OCA on Wed Nov 21 09:54:29 2007