8bt4

Publication Abstract from PubMed

Aerobic ribonucleotide reductases (RNRs) initiate synthesis of DNA building blocks by generating a free radical within the R2 subunit; the radical is subsequently shuttled to the catalytic R1 subunit through proton-coupled electron transfer (PCET). We present a high-resolution room temperature structure of the class Ie R2 protein radical captured by x-ray free electron laser serial femtosecond crystallography. The structure reveals conformational reorganization to shield the radical and connect it to the translocation path, with structural changes propagating to the surface where the protein interacts with the catalytic R1 subunit. Restructuring of the hydrogen bond network, including a notably short O-O interaction of 2.41 angstroms, likely tunes and gates the radical during PCET. These structural results help explain radical handling and mobilization in RNR and have general implications for radical transfer in proteins.

Structure of a ribonucleotide reductase R2 protein radical.,Lebrette H, Srinivas V, John J, Aurelius O, Kumar R, Lundin D, Brewster AS, Bhowmick A, Sirohiwal A, Kim IS, Gul S, Pham C, Sutherlin KD, Simon P, Butryn A, Aller P, Orville AM, Fuller FD, Alonso-Mori R, Batyuk A, Sauter NK, Yachandra VK, Yano J, Kaila VRI, Sjoberg BM, Kern J, Roos K, Hogbom M Science. 2023 Oct 6;382(6666):109-113. doi: 10.1126/science.adh8160. Epub 2023 , Oct 5. PMID:37797025^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.