title: A structural model for the rolA protein and its interaction with DNA.
abstract: The study of the plant oncogene rolA has been hampered by a lack of structural information. Here we show that, despite a lack of significant sequence similarity to proteins of known structure, the rolA sequence adopts a known fold; that of the papillomavirus E2 DNA-binding domain. This fold is reliably identified by modern threading programs, which consider predicted secondary structure, but not by others. Although the rolA sequence is only around 16% identical to those of the available template structures, a structural model could be built that performed well against protein structure verification programs. The adopted strategy involved alignment corrections, justified by multiple model building and evaluation, with particular attention paid to the hydrophobic core residues. We find that rolA protein is predicted to resemble the template proteins in two key aspects; existence as a dimer and ability to bind DNA. rolA protein has recently been shown experimentally to possess DNA binding ability. This model predicts Lys 24 and Arg 27 to be involved in sequence-specific interactions and eight other residues to hydrogen-bond phosphate groups of the DNA.
authors.affiliation: National Centre of Genetic Resources and Biotechnology, Cenargen/Embrapa, Brasilia, Brazil. daniel@cenargen.embrapa.br
authors.forename: D J
authors.initials: DJ
authors.lastname: Rigden
authors.forename: M
authors.initials: M
authors.lastname: Carneiro
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D052688:Bovine papillomavirus 1 / Q000737:chemistry / Q000235:genetics; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D011487:Protein Conformation; D012231:Rhizobium / Q000737:chemistry / Q000235:genetics / Q000472:pathogenicity; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C051550:E2 protein, Bovine papillomavirus; D014764:Viral Proteins; C096589:rolA protein, Agrobacterium rhizogenes; D004247:DNA