Enkelstrengige DNA-bindende eiwitten

Once the helicase unwinds DNA, the resulting separated, single-stranded DNA molecules can form hairpin loops by intra-strand pairing or double-stranded DNA by inter-strand pairing. 

These strands are also vulnerable to attack by nucleases that can digest the DNA.

To prevent this, single-strand DNA binding, or SSB, proteins bind to the single-stranded DNA in a sequential manner where the incoming SSB binds adjacent to the existing SSB.

This cooperative binding of the SSB proteins straightens and protects the parent DNA strand preventing the formation of the hair-pin loops or the rewinding of the DNA back into its double-stranded structure.

The SSB proteins attach tightly to the sugar-phosphate backbone of the DNA and leave the nitrogenous bases available for complementary nucleotide binding allowing for the formation of the daughter strand.