Specificity of Cellular DNA-Binding Sites of Microbial Populations in a Florida Reservoir
AUTOR(ES)
Paul, John H.
RESUMO
The substrate specificity of the DNA-binding mechanism(s) of bacteria in a Florida reservoir was investigated in short- and long-term uptake studies with radiolabeled DNA and unlabeled competitors. Thymine oligonucleotides ranging in size from 2 base pairs to 19 to 24 base pairs inhibited DNA binding in 20-min incubations by 43 to 77%. Deoxynucleoside monophosphates, thymidine, and thymine had little effect on short-term DNA binding, although several of these compounds inhibited the uptake of the radiolabel from DNA in 4-h incubations. Inorganic phosphate and glucose-1-phosphate inhibited neither short- nor long-term binding of [3H]- or [32P]DNA, indicating that DNA was not utilized as a phosphorous source in this reservoir. RNA inhibited both short- and long-term radiolabeled DNA uptake as effectively as unlabeled DNA. Collectively these results indicate that aquatic bacteria possess a generalized nucleic acid uptake/binding mechanism specific for compounds containing phosphodiester bonds and capable of recognizing oligonucleotides as short as dinucleotides. This binding site is distinct from nucleoside-, nucleotide-, phosphomonoester-, and inorganic phosphate-binding sites. Such a nucleic acid-binding mechanism may have evolved for the utilization of extracellular DNA (and perhaps RNA), which is abundant in many marine and freshwater environments.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=203171Documentos Relacionados
- Using electrostatic potentials to predict DNA-binding sites on DNA-binding proteins
- Production of dissolved DNA, RNA, and protein by microbial populations in a Florida reservoir.
- DNA-binding specificity and dimerization of the DNA-binding domain of the PEND protein in the chloroplast envelope membrane
- Highly repeated sites in the apolipoprotein(a) gene recognized by methylated DNA-binding protein, a sequence-specific DNA-binding protein.
- DNA-binding specificity of the fushi tarazu homeodomain.