The impact of single cysteine residue mutations on the replication terminator protein

Publication Type:
Journal Article
Biochemical and Biophysical Research Communications, 2003, 310 (4), pp. 1096 - 1103
Issue Date:
Filename Description Size
Thumbnail2010001714OK.pdf398.01 kB
Adobe PDF
Full metadata record
We report the structural and biophysical consequences of cysteine substitutions in the DNA-binding replication terminator protein (RTP) of Bacillus subtilis, that resulted in an optimised RTP mutant suitable for structural studies. The cysteine residue 110 was replaced with alanine, valine or serine. Protein secondary structure and stability (using circular dichroism spectropolarimetry), self-association (using analytical ultracentrifugation), and DNA-binding measurements revealed RTP.C110S to be the most similar mutant to wild-type RTP. The C110A and C110V.RTP mutants were less soluble, less stable and showed lower DNA-binding affinity. The structure of RTP.C110S, solved to 2.5Å resolution using crystallographic methods, showed no major structural perturbation due to the mutation. Heteronuclear NMR spectroscopic studies revealed subtle differences in the electronic environment about the site of mutation. The study demonstrates the suitability of serine as a substitute for cysteine in RTP and the high sensitivity of protein behaviour to single amino acid substitutions. © 2003 Elsevier kInc. All rights reserved.
Please use this identifier to cite or link to this item: