Single stranded binding protein: Difference between revisions

===Sandbox Single Stranded DNA-Binding Protein (SSB)===

'''Single-stranded DNA-binding protein''', or SSB, binds to single-stranded regions of DNA in order to prevent premature annealing, to protect the single-stranded DNA from being digested by nucleases, and to remove secondary structure from the DNA to allow other enzymes to function effectively upon it. Single-stranded DNA is produced during all aspects of DNA metabolism: replication, recombination and repair. As well as stabilizing this single-stranded DNA, SSB proteins bind to and modulate the function of numerous proteins involved in all of these processes.

<StructureSection load='1eyg' size='400' side='right' frame='true' caption='Structure of Single Stranded DNA-Binding Protein bound to ssDNA (PDB entry [[1eyg]])' scene=''>

==Structure==

SSB consists is a homotetramer that has a DNA binding domain which binds to a single strand of DNA. The tetramers consist of α-helices, β-sheets, and random coils. Each subunit contains an <scene name='56/566528/Alpha_helices/3'>α-helix</scene> and several <scene name='56/566528/Beta_sheets/1'>β-sheets</scene>. The secondary structure also includes a NH2 terminus, which consists of multiple positively charged amino acids. The DNA-binding domain lies within 115 amino acid residues from this terminus <ref>PMID: 2087220</ref>. The COOH terminus includes many acidic amino acids.  

and a protein n, which is used to help synthesize RNA primers for the lagging strand.  

</StructureSection>

==Binding Interactions between DNA and SSB of ''E. coli''==

Phe60 is an important DNA binding site. It has been shown to be the site for cross-linking.

<scene name='56/566528/Tryptophan_residues/1'>Tryptophan</scene> and Lysine residues