P53R2: Difference between revisions

The N-terminal residues of the monomer A can stabilize the B helix of the monomer B due to different interactions. R41 of the monomer A forms a salt bridge with E119 of monomer A. This interaction permits the formation of a H-bond between R40 of monomer A with G101of monomer B. Furthermore K37 in monomer A forms a salt bridge with E105 of monomer B and this stabilize its B helix. All the interactions allow D100 of monomer B to be well oriented to bind Fe1 (see Figure below, Smith P. et al., 2009, 2.6 A ° X-ray Crystal Structure of Human p53R2, a p53-Inducible Ribonucleotide Reductase).

On the contrary R40 of monomer B is bound to E119 of the same monomer and so it can not bind to G101 of the monomer A and the consequence is that F42 disturb the B helix of monomer A. D100 can not interact with Fe1. This explain why the monomer A has only one iron-binding site whereas the monomer B has two (see Figure below, Smith P. et al., 2009, 2.6 A ° X-ray Crystal Structure of Human p53R2, a p53-Inducible Ribonucleotide Reductase <ref>PMID:19728742</ref>).