Table of Contents
Journal of Amino Acids
Volume 2012, Article ID 848037, 10 pages
http://dx.doi.org/10.1155/2012/848037
Research Article

Role of Linkers between Zinc Fingers in Spacing Recognition by Plant TFIIIA-Type Zinc-Finger Proteins

1Disease Resistant Crops Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
2Department of Biological Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda, Chiba 278-8510, Japan

Received 28 April 2011; Revised 1 August 2011; Accepted 4 August 2011

Academic Editor: Nancy C. Horton

Copyright © 2012 Setsuko Fukushima et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The EPF family of plant TFIIIA-type zinc-finger (ZF) proteins (ZPTs) is characterized by long linkers separating ZF motifs. We previously reported that two-fingered ZPTs bind to two tandem core sites that are separated by several base pairs, each ZF making contact with one core site. Here we report further characterization of DNA-binding activities of ZPTs using four family members, ZPT2-14, ZPT2-7, ZPT2-8, and ZPT2-2, having inter-ZF linkers of different lengths and sequences, to investigate the correlation of the length and/or sequence of the linker with preference for the spacing between core sites in target DNAs. Selected and amplified binding site (SAAB)-imprinting assays and gel mobility shift assays prompted three conclusions. (1) The four ZPTs have common specificity for core binding sites—two AGT(G)/(C)ACTs separated by several nucleotides. (2) The four ZPTs prefer a spacing of 10 bases between the core sites, but each ZPT has its own preference for suboptimal spacing. (3) At a particular spacing, two zinc fingers may bind to the core sites on both strands. The results provide new information about how the diversity in linker length/sequence affects DNA-sequence recognition in this protein family.