Poly(dG)-poly(dC) DNA appears shorter than poly(dA)-poly(dT) and possibly adopts an A-related conformation on a mica surface under ambient conditions.
Three types of DNA: approximately 2700 bp polydeoxyguanylic olydeoxycytidylic acid [poly(dG)-poly(dC)], approximately 2700 bp polydeoxyadenylic polydeoxythymidylic acid [poly(dA)-poly(dT)] and 2686 bp linear plasmid pUC19 were deposited on a mica surface and imaged by atomic force microscopy. Contour length measurements show that the average length of poly(dG)-poly(dC) is approximately 30% shorter than that of poly(dA)-poly(dT) and the plasmid. This led us to suggest that individual poly(dG)-poly(dC) molecules are immobilized on mica under ambient conditions in a form which is likely related to the A-form of DNA in contrast to poly(dA)-poly(dT) and random sequence DNA which are immobilized in a form that is related to the DNA B-form.
Borovok
Natalia
N
Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel.
Molotsky
Tatiana
T
Ghabboun
Jamal
J
Cohen
Hezy
H
Porath
Danny
D
Kotlyar
Alexander
A
D000538:Aluminum Silicates / Q000737:chemistry*; D044704:DNA, A-Form / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000648:ultrastructure; D011067:Poly dA-dT / Q000737:chemistry*; D011089:Polydeoxyribonucleotides / Q000737:chemistry*
D000538:Aluminum Silicates; D044704:DNA, A-Form; D011089:Polydeoxyribonucleotides; D011067:Poly dA-dT; C019530:poly(dC-dG); C011934:mica