3VHQ

Crystal structure of the Ca6 site mutant of Pro-SA-subtilisin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.171 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Requirement of Ca(2+) Ions for the Hyperthermostability of Tk-Subtilisin from Thermococcus kodakarensis

Uehara, R.Takeuchi, Y.Tanaka, S.I.Takano, K.Koga, Y.Kanaya, S.

(2012) Biochemistry 51: 5369-5378

  • DOI: 10.1021/bi300427u

  • PubMed Abstract: 
  • Tk-subtilisin, a hyperthermostable subtilisin-like serine protease from Thermococcus kodakarensis, matures from the inactive precursor, Pro-Tk-subtilisin (Pro-TKS), upon autoprocessing and degradation of the propeptide (Tkpro). It contains seven Ca(2 ...

    Tk-subtilisin, a hyperthermostable subtilisin-like serine protease from Thermococcus kodakarensis, matures from the inactive precursor, Pro-Tk-subtilisin (Pro-TKS), upon autoprocessing and degradation of the propeptide (Tkpro). It contains seven Ca(2+) ions. Four of them (Ca2-Ca5) are responsible for folding of Tk-subtilisin. In this study, to clarify the role of the other three Ca(2+) ions (Ca1, Ca6, and Ca7), we constructed Pro-TKS derivatives lacking the Ca1 ion (Pro-TKS/ΔCa1), Ca6 ion (Pro-TKS/ΔCa6), and Ca7 ion (Pro-TKS/ΔCa7), and their active site mutants (Pro-S324A/ΔCa1, Pro-S324A/ΔCa6, and Pro-S324A/ΔCa7, respectively). Pro-TKS/ΔCa6 and Pro-TKS/ΔCa7 fully matured into their active forms upon incubation at 80 °C for 30 min as did Pro-TKS. The mature enzymes were as active as Tk-subtilisin at 80 °C, indicating that the Ca6 and Ca7 ions are not important for activity. In contrast, Pro-TKS/ΔCa1 matured poorly at 80 °C because of the instability of its mature domain. The enzymatic activity of Tk-subtilisin/ΔCa1 was determined to be 50% of that of Tk-subtilisin using the refolded protein. This result suggests that the Ca1 ion is required for the maximal activity of Tk-subtilisin. The refolding rates of all Pro-S324A derivatives were comparable to that of Pro-S324A (active site mutant of Pro-TKS), indicating that these Ca(2+) ions are not needed for folding of Tk-subtilisin. The stabilities of Pro-S324A/ΔCa1 and Pro-S324A/ΔCa6 were decreased by 26.6 and 11.7 °C, respectively, in T(m) compared to that of Pro-S324A. The half-lives of Tk-subtilisin/ΔCa6 and Tk-subtilisin/ΔCa7 at 95 °C were 8- and 4-fold lower than that of Tk-subtilisin, respectively. These results suggest that the Ca1, Ca6, and Ca7 ions, especially the Ca1 ion, contribute to the hyperthermostabilization of Tk-subtilisin.


    Organizational Affiliation

    Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Tk-subtilisin
A
398Thermococcus kodakarensis (strain ATCC BAA-918 / JCM 12380 / KOD1)Mutation(s): 2 
EC: 3.4.21.-
Find proteins for P58502 (Thermococcus kodakarensis (strain ATCC BAA-918 / JCM 12380 / KOD1))
Go to UniProtKB:  P58502
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.171 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 73.434α = 90.00
b = 92.780β = 90.00
c = 124.279γ = 90.00
Software Package:
Software NamePurpose
BL38data collection
HKL-2000data scaling
MOLREPphasing
REFMACrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-07-11
    Type: Initial release