Mutual synergistic protein folding in split intein.
Inteins are intervening protein sequences that undergo self-excision from a precursor protein with the concomitant ligation of the flanking polypeptides. Split inteins are expressed in two separated halves, and the recognition and association of two halves are the first crucial step for initiating trans-splicing. In the present study, we carried out the structural and thermodynamic analysis on the interaction of two halves of DnaE split intein from Synechocystis sp. PCC6803. Both isolated halves (IN and IC) are disordered and undergo conformational transition from disorder to order upon association. ITC (isothermal titration calorimetry) reveals that the highly favourable enthalpy change drives the association of the two halves, overcoming the unfavourable entropy change. The high flexibility of two fragments and the marked thermodynamic preference provide a robust association for the formation of the well-folded IN/IC complex, which is the basis for reconstituting the trans-splicing activity of DnaE split intein.
CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
Yuchuan
Y
Zheng
Qin
Q
Wu
Chunyu
C
Wang
Min-Qun
MQ
Xu
Yangzhong
Y
Liu
D002942:Circular Dichroism; D003001:Cloning, Molecular; D004258:DNA Polymerase III / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D047668:Inteins / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy; D017510:Protein Folding; D019154:Protein Splicing; D046939:Synechocystis / Q000737:chemistry*; D013816:Thermodynamics
C074904:DNA polymerase III, alpha subunit; D004258:DNA Polymerase III