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Synthesis and characterization of a 29‐amino acid residue DNA‐binding peptide derived from α/β‐type small, acid‐soluble spore proteins (SASP) of bacteria
Author(s) -
Rao Hai,
Mohr Scott C.,
Fairhead Heather,
Setlow Peter
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80876-i
Subject(s) - peptide , circular dichroism , dna , polynucleotide , peptide sequence , biochemistry , residue (chemistry) , dimer , chemistry , amino acid , bacillus subtilis , stereochemistry , biology , bacteria , gene , genetics , organic chemistry
A 29‐amino acid residue peptide (SASP‐peptide) derived from the sequence of the putative DNA‐contacting portion at the carboxyl terminus of an α/β‐type small, acid‐soluble spore protein (SASP) of Bacillus subillis has been synthesized by automated solid‐phase methods and tested for its ability to interact with DNA. Circular dichroism (CD) spectroscopy reveals an interaction between this SASP‐peptidc and DNA, both by an increase in α‐helix content of the peplide (which alone has a mostly random conformation) and by enhancement of the 275‐nm CD band of the DNA. In contrast to results with intact α/β‐type SASP, however, the peptide does not induce a B → A cenformational transition in the DNA. The SASP‐peptide also binds to poly(dG)·poly(dC) and prtects this polynucleotide against DNase I digestion and UV light‐induced cylosine dimer formation, parallel to Findings made previously with native α/β‐type SASP. The results confirm the hypothesis that the carboxyl‐terminal region of the α/β‐type SASP directly contacts DNA and possesses some, but not all, or the functional characteristics of the intact molecule.