The transcription regulator, tvMyb1, is the first Myb family protein identified in Trichomonas vaginalis. Using an electrophoretic mobility shift assay, we defined the amino-acid sequence from Lys(35) to Ser(141) (tvMyb1(35-141)) as the minimal DNA-binding domain, encompassing two Myb-like DNA-binding motifs (designated as R2 and R3 motifs) and an extension of 10 residues at the C-terminus. NMR...

The homing endonuclease I-PpoI severely bends its DNA target, resulting in significant deformations of the minor and major groove near the scissile phosphate groups. To study the role of conformational changes within the protein catalyst and the DNA substrate, we have determined the structure of the enzyme in the absence of bound DNA, performed gel retardation analyses of DNA binding and bendin...

Ion-mediated interaction is critical to the structure and stability of nucleic acids. Recent experiments suggest that the multivalent ion-induced aggregation of double-stranded (ds) RNAs and DNAs may strongly depend on the topological nature of helices, while there is still lack of an understanding on the relevant ion-mediated interactions at atomistic level. In this work, we have directly calc...

The POU family transcription factor Oct4 plays pivotal roles in regulating pluripotency and somatic cell reprogramming. Previous studies have indicated an important role for major groove contacts in Oct4-DNA recognition; however, the contributions of the RK motif in the POUh domain and the linker segment joining the two DNA-binding domains remain poorly understood. Here, by combining molecular ...

The metallointercalator Lambda-1-Rh(MGP)2phi5+ binds tightly and specifically to the site 5'-CATATG-3' in the major groove of double helical DNA by a combination of direct readout and shape selection. To examine competitive interactions between this small metal complex and a DNA-binding transcription factor, the preferred binding site for Lambda-1-Rh(MGP)2phi5+ was engineered into the AP-1 reco...

To determine the sequence specificity of dimeric Ss-LrpB, a high resolution contact map was constructed and a saturation mutagenesis conducted on one half of the palindromic consensus box. Premodification binding interference indicates that Ss-LrpB establishes most of its tightest contacts with a single strand of two major groove segments and interacts with the minor groove at the center of the...

[This corrects the article DOI: 10.1371/journal.pone.0150189.].

PT-ACRAMTU ([PtCl(en)(ACRAMTU-S)](NO(3))(2), en = ethane-1,2-diamine, ACRAMTU = 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea) is a cytotoxic platinum-acridine conjugate previously shown to form adducts with the N3 endocyclic nitrogen of adenine in the DNA minor groove. This unusual observation and our prior determination of the pronounced 5'-TA/TA base-step affinity of the drug have prom...

The use of gene therapeutics, including short interfering RNA (siRNA), is limited by the lack of efficient delivery systems. An appealing approach to deliver gene therapeutics involves noncovalent complexation with cell penetrating peptides (CPPs) which are able to penetrate the cell membranes of mammals. Although a number of CPPs have been discovered, our understanding of their complexation an...