Dimeric configuration of SeqA bound to a pair of hemi-sites

Copyright information:Taken from "Dimeric configuration of SeqA protein bound to a pair of hemi-methylated GATC sequences"Nucleic Acids Research 2005;33(5):1524-1531.Published online 14 Mar 2005PMCID:PMC1065253.© The Author 2005. Published by Oxford University Press. All rights reserved To observe the complexes of SeqA with hemi-methylated DNA, 10 μl of a reaction mixture in buffer A containing SeqA (0.2–20 ng), the indicated DNA (50 fmol) and no glycerol was incubated for 15 min at 32°C, and the mixture was directly deposited on freshly cleaved mica. After further incubation for 30 min at room temperature, the specimen was gently washed with buffer A, fixed with 0.5% glutaraldehyde for 2–3 min, and washed several times again with buffer A. Images were recorded in the tapping mode in aqueous solution. () Representative images of complexes formed by SeqA and the 21 bp spacing DNA (upper panel), and a computerized 3D view of the complexes (lower panel) with a schematic picture (inner box). The arrowhead points to the portion of SeqA opened up as a result of binding to the DNA. () Relative frequency of the DNA bending angles in the complexes of SeqA with 21 bp spacing DNA. The degree of DNA bending was measured by drawing lines from the ends of the DNA strand to the apparent bending point of the bound DNA. () Representative images of complexes formed by SeqA and the 11 bp spacing DNA, and a computerized 3D view of the complexes. () Representative images of complexes formed by SeqA and 31 bp spacing DNA, and a computerized 3D view of the complexes. () Representative images of complexes formed by SeqA and 16 bp spacing DNA, and a computerized 3D view of the complexes. All the horizontal scale bars represent 20 nm, and the upright scale bars represent height of the particles from the baseline to the top. () Cartoon of the complexes formed between SeqA and a pair of hemi-sites spaced increasing distances apart.