Filamentous bacterial viruses.
D A Marvin,Barbara Hohn +1 more
469
TL;DR: X-ray fibre diffraction patterns of the Pf 1 species of virus at 4°C, oriented in a strong magnetic field, give three-dimensional data to 4 A resolution, and an electron density map calculated from native virus and a single iodine derivative, shows a helix pitch of 5.9 A.
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Abstract: The filamentous bacterial virus is a simple and well-characterized model system for studying how genetic information is transformed into molecular machines. The viral DNA is a single-stranded circle coding for about 10 proteins. The major viral coat protein is largely α-helical, with about 46 amino acid residues. Several thousand identical copies of this protein in a helical array form a hollow cylindrical tube 1–2μ long, of outer diameter 60 A and inner diameter 20 A, with the twisted circular DNA extending down the core of the tube. Before assembly, the viral coat protein spans the cell membrane, and assembly involves extrusion of the coat from the membrane. X-ray fibre diffraction patterns of the Pf 1 species of virus at 4°C, oriented in a strong magnetic field, give three-dimensional data to 4 A resolution. An electron density map calculated from native virus and a single iodine derivative, using the maximum entropy technique, shows a helix pitch of 5.9 A. This may indicate a stretched A-helix, or it may indicate a partially 310 helix conformation, resulting from the fact that the coat protein is an integral membrane protein before assembly, and is still in the hydrophobic environment of other coat proteins after assembly.
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References
Physical Principles in the Construction of Regular Viruses
Donald L. D. Caspar,A. Klug +1 more
TL;DR: The authors' designs obey strict icosahedral symmetry, with the asymmetric unit in each case containing a heterodimer that comprises one subunit from each of the two components.
2.5K
Codon--anticodon pairing: the wobble hypothesis.
TL;DR: In this paper, it is suggested that while the standard base pairs may be used rather strictly in the first two positions of the triplet, there may be some wobble in the pairing of the third base.
1.9K
On the origin of mitosing cells
TL;DR: During the course of the evolution of mitosis, photosynthetic plastids were symbiotically acquired by some of these protozoans to form the eukaryotic algae and the green plants.
1.6K
Chromosome replication and the division cycle of Escherichia coli B/r
TL;DR: It is suggested that the replication of the bacterial genome during the division cycle of Escherichia coli Br growing with doubling times between approximately 20 and 60 minutes can be described by two constants: C and D, the time for a replication point to traverse the genome.
1.2K