Journal article
Regulatory Functions of the N-terminal Domain of the 70-kDa Subunit of Replication Protein A (RPA)
The Journal of biological chemistry, Vol.283(31), pp.21559-21570
08/01/2008
DOI: 10.1074/jbc.M802450200
PMCID: PMC2490791
PMID: 18515800
Abstract
Replication protein A (RPA) is the major single-stranded DNA-binding
protein in eukaryotes. RPA is composed of three subunits of 70, 32, and 14
kDa. The N-terminal domain of the 70-kDa subunit (RPA70) has weak DNA binding
activity, interacts with proteins, and is involved in cellular DNA damage
response. To define the mechanism by which this domain regulates RPA function,
we analyzed the function of RPA forms containing a deletion of the N terminus
of RPA70 and mutations in the phosphorylation domain of RPA (N-terminal 40
amino acids of the 32-kDa subunit). Although each individual mutation has only
modest effects on RPA activity, a form combining both phosphorylation mimetic
mutations and a deletion of the N-terminal domain of RPA70 was found to have
dramatically altered activity. This combined mutant was defective in binding
to short single-stranded DNA oligonucleotides and had altered interactions
with proteins that bind to the DNA-binding core of RPA70. These results
indicate that in the absence of the N-terminal domain of RPA70, a negatively
charged phosphorylation domain disrupts the activity of the core DNA-binding
domain of RPA. We conclude that the N-terminal domain of RPA70 functions by
interacting with the phosphorylation domain of the 32-kDa subunit and blocking
undesirable interactions with the core DNA-binding domain of RPA. These
studies indicate that RPA conformation is important for regulating RPA-DNA and
RPA-protein interactions.
Details
- Title: Subtitle
- Regulatory Functions of the N-terminal Domain of the 70-kDa Subunit of Replication Protein A (RPA)
- Creators
- Sara K Binz - Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242-2600Marc S Wold - Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242-2600
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.283(31), pp.21559-21570
- DOI
- 10.1074/jbc.M802450200
- PMID
- 18515800
- PMCID
- PMC2490791
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- American Society for Biochemistry and Molecular Biology
- Language
- English
- Date published
- 08/01/2008
- Academic Unit
- Radiation Oncology; Biochemistry and Molecular Biology
- Record Identifier
- 9984024409702771
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