Biomedical subjects

A Sokolova

Publications and source records attributed to A Sokolova.

2 recordsLinked to original sources

PubMed2004

Synergistic use of synchrotron radiation techniques for biological samples in solution: a case study on protein-ligand recognition by the peroxisomal import receptor Pex5p.

Circular dichroism spectropolarimetry and X-ray scattering data, obtained using synchrotron radiation, can yield information about the secondary and tertiary structure of proteins in solution. These techniques have been used to analyse the architecture and shape of a complex of two proteins in solution. The crystal structures of two separate proteins, the C-terminal domain of Pex5p and SCP2, are available but their complex has not previously been structurally characterized. Circular dichroism spectropolarimetry indicated that complex formation requires little secondary structure rearrangement. X-ray scattering data fit an elongated irregular 'shoe'-shaped particle of the complex of the two proteins, with dimensions of the order of 30 A x 40 A x 90 A. Comparison with the known crystal structures suggests that this 'shoe' shape requires a conformational change of the C-terminus of SCP2 to appropriately locate its peroxisomal targeting signal type-1 recognition motif into the binding pocket of the Pex5p receptor. Implications of the combined use of synchrotron-based circular dichroism spectropolarimetry and X-ray scattering in structural biology and proteomics are discussed.

Binding Sites↗

PubMed2001

Solution structure of bacteriophage PRD1 vertex complex.

Bacteriophage PRD1 is a prototype of viruses with an internal membrane. The icosahedral capsid and major coat protein share structural similarity with the corresponding structures of adenovirus. The present study further explores similarities between these viruses, considering the 5-fold vertex assemblies. The vertex structure of bacteriophage PRD1 consists of proteins P2, P5, and P31. The vertex complex mediates host cell binding and controls double-stranded DNA delivery. Quaternary structures and interactions of purified spike proteins were studied by synchrotron radiation x-ray solution scattering. Low resolution models of the vertex proteins P5, P2, and P31 were reconstructed ab initio from the scattering data. Protein P5 is a long trimer that resembles the adenovirus spike protein pIV. The receptor-binding protein P2 is a 15.5-nm long, thin monomer and does not have an adenovirus counterpart. P31 forms a pentameric base with a maximum diameter of 8.5 nm, which is thinner than the adenovirus penton pIII. P5 further polymerize into a nonameric form ((P5(3))(3)). In the presence of P31, P5 associates into a P5(6):P31 complex. The constructed models of these assemblies provided support for a model of vertex assembly onto the virion. Although similar in overall architecture, clear differences between PRD1 and adenovirus spike assemblies have been revealed.

Bacteriophage PRD1↗