title: Insights into the Functional Roles of N-Terminal and C-Terminal Domains of Helicobacter pylori DprA.
abstract: DNA processing protein A (DprA) plays a crucial role in the process of natural transformation. This is accomplished through binding and subsequent protection of incoming foreign DNA during the process of internalization. DprA along with Single stranded DNA binding protein A (SsbA) acts as an accessory factor for RecA mediated DNA strand exchange. H. pylori DprA (HpDprA) is divided into an N-terminal domain and a C- terminal domain. In the present study, individual domains of HpDprA have been characterized for their ability to bind single stranded (ssDNA) and double stranded DNA (dsDNA). Oligomeric studies revealed that HpDprA possesses two sites for dimerization which enables HpDprA to form large and tightly packed complexes with ss and dsDNA. While the N-terminal domain was found to be sufficient for binding with ss or ds DNA, C-terminal domain has an important role in the assembly of poly-nucleoprotein complex. Using site directed mutagenesis approach, we show that a pocket comprising positively charged amino acids in the N-terminal domain has an important role in the binding of ss and dsDNA. Together, a functional cross talk between the two domains of HpDprA facilitating the binding and formation of higher order complex with DNA is discussed.
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Gajendradhar R
authors.initials: GR
authors.lastname: Dwivedi
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Kolluru D
authors.initials: KD
authors.lastname: Srikanth
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Praveen
authors.initials: P
authors.lastname: Anand
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Javed
authors.initials: J
authors.lastname: Naikoo
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: N S
authors.initials: NS
authors.lastname: Srilatha
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Desirazu N
authors.initials: DN
authors.lastname: Rao
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009698:Nucleoproteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C093815:DprA protein, bacteria; D008565:Membrane Proteins; D009698:Nucleoproteins; D011994:Recombinant Proteins; D004247:DNA; D011938:Rec A Recombinases