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Bacteriophage N4 large terminase: expression, purification and X‐ray crystallographic analysis
Author(s) -
Wangchuk Jigme,
Prakash Prem,
Bhaumik Prasenjit,
Kondabagil Kiran
Publication year - 2018
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 37
ISSN - 2053-230X
DOI - 10.1107/s2053230x18003084
Subject(s) - capsid , bacteriophage , biology , escherichia coli , genome , crystallography , microbiology and biotechnology , chemistry , virus , virology , gene , genetics
Genome packaging is a critical step in the assembly of dsDNA bacteriophages and is carried out by a powerful molecular motor known as the large terminase. To date, wild‐type structures of only two large terminase proteins are available, and more structural information is needed to understand the genome‐packaging mechanism. Towards this goal, the large and small terminase proteins from bacteriophage N4, which infects the Escherichia coli K12 strain, have been cloned, expressed and purified. The purified putative large terminase protein hydrolyzes ATP, and this is enhanced in the presence of the small terminase. The large terminase protein was crystallized using the sitting‐drop vapour‐diffusion method and the crystal diffracted to 2.8 Å resolution using a home X‐ray source. Analysis of the X‐ray diffraction data showed that the crystal belonged to space group P 2 1 2 1 2 1 , with unit‐cell parameters a = 53.7, b = 93.6, c = 124.9 Å, α = β = γ = 90°. The crystal had a solvent content of 50.2% and contained one molecule in the asymmetric unit.