Binding of tachyplesin I to DNA revealed by footprinting analysis: significant contribution of secondary structure to DNA binding and implication for biological action.
In view of the cationic amphipathic structure of tachyplesin I and antiparallel beta-sheet as a general DNA binding motif, DNA binding of the antimicrobial peptide has been examined. Several footprinting-like techniques using DNase I protection, dimethyl sulfate protection, and bleomycin- (BLM-) induced DNA cleavage were applied in this study. Some distinct footprints with DNase I are detected, and also the sequence-specific cleavage mode of the BLM-Fe(II) complex clearly is altered in the presence of tachyplesin I. In addition, methylation of the N-7 residue of guanine situated in the DNA major groove is not entirely inhibited (or activated) by tachyplesin I. The results suggest that tachyplesin I interacts with the minor groove of DNA duplex. Disappearance of the footprints by dithiothreitol-treated tachyplesin I and Ala-tachyplesin strongly suggests a significant contribution of secondary structure containing an antiparallel beta-sheet to the DNA binding of tachyplesin I. This is the first report on DNA interaction with a small peptide which contains a unique antiparallel beta-sheet structure. The mechanism for antimicrobial action of tachyplesin I has also been inferred.
Institute for Chemical Research, Kyoto University, Japan.
A
A
Yonezawa
J
J
Kuwahara
N
N
Fujii
Y
Y
Sugiura
D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism; D023181:Antimicrobial Cationic Peptides; D001483:Base Sequence; D001665:Binding Sites; D001761:Bleomycin / Q000494:pharmacology; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins; D003850:Deoxyribonuclease I; D004229:Dithiothreitol / Q000494:pharmacology; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010456:Peptides, Cyclic; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013463:Sulfuric Acid Esters
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D004268:DNA-Binding Proteins; D010455:Peptides; D010456:Peptides, Cyclic; D013463:Sulfuric Acid Esters; D001761:Bleomycin; C057636:tachyplesin peptide, Tachypleus tridentatus; D004247:DNA; D003850:Deoxyribonuclease I; C007482:dimethyl sulfate; D004229:Dithiothreitol