Purification, crystallization and preliminary X‐ray diffraction studies of the bacteriophage φ29 connector particle
1998; Wiley; Volume: 430; Issue: 3 Linguagem: Inglês
10.1016/s0014-5793(98)00672-3
ISSN1873-3468
AutoresAlı́cia Guasch, A. Parraga, Joan Pous, José Valpuesta, José L. Carrascosa, Miquel Coll,
Tópico(s)Bacterial Genetics and Biotechnology
ResumoThe connector or portal particle from double‐stranded DNA bacteriophage φ29 has been crystallized. This structure, which connects the head of the virus with the tail and plays a central role in prohead assembly and DNA packaging and translocation, is formed by 12 subunits of the p10 protein and has a molecular weight of 430 kDa. The connector structure was proteolysed with endoproteinase Glu‐C from Staphylococcus aureus V8, which removes 13 and 18 amino acids from the amino‐ and carboxy‐terminal regions of the p10 protein, respectively. Two crystal forms were grown from drops containing an alcohol solution and paraffin oil. Crystals of form I are monoclinic, space group C2 with cell dimensions a =416.86 Å, b =227.62 Å, c =236.68 Å and β=96.3° and contain four connector particles per asymmetric unit. Crystals of form II are tetragonal, space group P4 2 2 1 2 with cell dimensions a = b =170.2 Å, c =156.9 Å and contain half a particle per asymmetric unit. X‐ray diffraction data from both native crystal forms have been collected to 6.0 and 3.2 Å respectively, using synchrotron radiation. Crystals of form II are likely to have the same packing arrangement as the two‐dimensional crystals analyzed previously by electron microscopy.
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