OBFC1 Human

Oligonucleotide/oligosaccharide-binding (OB) fold is a structural motif found in a variety of proteins across different species, including prokaryotes and eukaryotes. This motif is known for its ability to bind single-stranded DNA (ssDNA) or RNA with high affinity. One of the notable proteins containing this motif is the human single-stranded DNA-binding protein 1 (hSSB1), which plays a crucial role in the DNA damage response (DDR).

The OB fold is characterized by a beta-barrel structure that forms a binding surface for nucleic acids. In hSSB1, the OB fold is located at the N-terminus and is responsible for binding to ssDNA. This binding is essential for the protein’s role in maintaining genomic stability, particularly during DNA replication and repair processes .

hSSB1 is rapidly recruited to sites of DNA damage, where it facilitates the formation of repair foci by interacting with other DDR proteins such as BRCA1 and RAD51. Recent studies have shown that the OB fold of hSSB1 also binds to poly(ADP-ribose) (PAR), a polymer synthesized by PARP enzymes in response to DNA damage . This interaction is crucial for the early recruitment of hSSB1 to DNA lesions, highlighting the importance of the OB fold in the DDR .

Given its critical role in DNA repair, hSSB1 and other OB fold-containing proteins are of significant interest in cancer research. Targeting these proteins could enhance the efficacy of existing therapies that induce DNA damage, such as radiation and certain chemotherapeutic agents . Additionally, understanding the mechanisms by which OB fold proteins contribute to genome stability could lead to the development of novel therapeutic strategies for diseases characterized by genomic instability .