Internal disulfide bond acts as a switch for intein activity.
Michael C Nicastri1, Kristina Xega, Lingyun Li
1Department of Chemistry, College of the Holy Cross, Worcester, Massachusetts 01610, United States.
Biochemistry
|August 3, 2013
Summary
Inteins are protein fragments that splice themselves out, joining other protein parts. This Mma intein
Area of Science:
- Biochemistry
- Molecular Biology
- Protein Chemistry
Background:
- Inteins are protein sequences that excise themselves from precursor proteins and ligate the flanking exteins.
- The intein from Methanoculleus marisnigri (Mma) DNA polymerase II (DP2) subunit facilitates protein splicing.
- Protein splicing can be regulated by environmental factors, such as redox conditions.
Purpose of the Study:
- To investigate the protein splicing activity of the Mma intein.
- To explore the redox sensitivity of Mma intein-mediated protein splicing.
- To understand the potential physiological role of protein splicing.
Main Methods:
- Overexpression of the Mma intein in E. coli under varying redox conditions.
- Analysis of protein splicing efficiency using biochemical assays.
- Investigation of disulfide bond formation within the intein.
Main Results:
- The Mma intein promotes protein splicing.
- Protein splicing is inhibited under non-reducing conditions due to disulfide bond formation between internal cysteine residues.
- Redox sensitivity results in differential splicing activity in various E. coli strains and cellular compartments.
Conclusions:
- The Mma intein's activity is redox-dependent.
- Disulfide bond formation is a key mechanism for controlling Mma intein splicing.
- Redox-controlled protein splicing suggests a potential physiological role for this process in anaerobic organisms.
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