Expression, purification, crystallization and preliminary X-ray diffraction analysis of a lactococcal bacteriophage small terminase subunit.
Acta Crystallogr Sect F Struct Biol Cryst Commun
; 69(Pt 3): 275-9, 2013 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-23519803
ABSTRACT
Terminases are enzymes that are required for the insertion of a single viral genome into the interior of a viral procapsid by a process referred to as 'encapsulation or packaging'. Many double-stranded DNA viruses such as bacteriophages T3, T4, T7, λ and SPP1, as well as herpes viruses, utilize terminase enzymes for this purpose. All the terminase enzymes described to date require two subunits, a small subunit referred to as TerS and a large subunit referred to as TerL, for in vivo activity. The TerS and TerL subunits interact with each other to form a functional hetero-oligomeric enzyme complex; however the stoichiometry and oligomeric state have not been determined. We have cloned, expressed and purified recombinant small terminase TerS from a 936 lactococcal bacteriophage strain ASCC454, initially isolated from a dairy factory. The terminase was crystallized using a combination of nanolitre sitting drops and vapour diffusion using sodium malonate as the precipitant, and crystallization optimized using standard vapour-diffusion hanging drops set up in the presence of a nitrogen atmosphere. The crystals belong to the P2 space group, with unit-cell parameters a=73.93, b=158.48, c=74.23â
Å, and diffract to 2.42â
Å resolution using synchrotron radiation. A self-rotation function calculation revealed that the terminase oligomerizes into an octamer in the asymmetric unit, although size-exclusion chromatography suggests that it is possible for it to form an oligomer of up to 13 subunits.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bacteriófagos
/
Proteínas Virais
/
Subunidades Proteicas
/
Endodesoxirribonucleases
Idioma:
En
Revista:
Acta Crystallogr Sect F Struct Biol Cryst Commun
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Austrália