Unformatted text preview: air is 36°.
An image of this DNA from a cell was taken, shown at the right.
For this supercoiled form of the plasmid specify the values of the following
(i) Twist (in turns)_________
(ii) Linking number_________
(iv) Assume that the plasmid is relaxed and forms a ﬂat circle. What is the
circumference of the circle? Q1C. 2’-3’ dideoxy nucleotide triphosphates are potent inhibitors of DNA replication. Explain why
these molecules block DNA replication. (2 points) BLOSUM Matrix Colied Coils Lea handed supercoil of two right handed helices Parallel or an;- parallel coiled coil Hydrophobic residues pabern: i, i+7 (heptad repeat) Iden;ty of residues: Residues a and d are usually hydrophobic to allow packing and forma;on of hydrophobic core. However, occasionally they are polar to determine the ‘register’. Residues e and g are oaen charged – can provide ionic interac;ons Parallel coiled coil: a from helix 1 interacts with a from helix 2 d from helix 1 interacts with d from helix 2 g from helix 1 interacts with e from helix 2 e from helix 1 interacts with g from helix 2 An;- Parallel coiled coil: a from helix 1 interacts with d from helix 2 d from helix 1 interacts with a from helix 2 g from helix 1 interacts with g
from helix 2 e from helix 1 interacts with e from helix 2 UC Berkeley, Chem C130/MCB 100A, Fall 2010, Mid-term Exam 1. Your Name___________________________ Q4. (20 points)
Q4A. (10 points) Shown below is a schematic diagram of two helices forming a parallel coiled coil. Consider two small proteins, A and B, of 14 residues each that are made up of only the following four
amino acids: L, Q, E, K.
Design sequences for A and B so that the helices obey the following rules:
1. Helix A forms a p...
View Full Document
- Fall '09