2e1p
Crystal structure of pro-Tk-subtilisinCrystal structure of pro-Tk-subtilisin
Structural highlights
Function[TKSU_THEKO] Has a broad substrate specificity with a slight preference to large hydrophobic amino acid residues at the P1 position. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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