BCHM 4116 1st Edition Lecture 4 Outline of Last Lecture I. Structural transitions of DNAII. Implication for nucleic acid hybridization Outline of Current Lecture I. Tertiary Structure in DNA II. L = T + WIII. SupercoilIV. DNAV. The secondary and tertiary structures of RNAsCurrent LectureI. Tertiary Structure in DNAa. Spiral around an imaginary toroidb. DNA interwinds and wraps about itselfc. Long linear DNA loops, ends restrained i. DNA attached to nuclearmatrixii. 1 end fixed so forms supercoilsiii. Make sure as you transcribe release stress/tensioniv. Enzyme topoisomerase I dues this by cutting 1 line to release pressure and seals back when finished v. Enzyme topoisomerase II does this by cutting both strands (And will seal when done) vi. DNA gyrase is a topoisomerase that introduces negative supercoil into DNA II. L = T + W a. L = linking number i. Number of times two strands are intertwined b. T = twisti. Number of helical turnsc. W = writhe i. Number of supercoils III. Supercoil a. Negative supercoil: more relaxed between the two twisted strandb. Positive supercoil: more tight These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.IV. DNAa. DNA is negatively charged b. Histone is positively charged i. This is why DNA wraps around histone c. “histone code” V. The secondary and tertiary structures of RNAsa. Pseudouridine: N- glycosidic which would have linked base to sugar via N but in this case base is linked to sugar via
View Full Document
Unlocking...