Crystal structures of Entamoeba histolytica lysyl‐tRNA synthetase reveal conformational changes upon lysine binding and a specific helix bundle domain

摘要

TheclassIIlysyl‐tRNAsynthetases(KRS)areconservedaminoacyl‐tRNAsynthetasesthatattachlysinetothecognatetRNAinatwo‐stepmechanism.TheenzymefromtheparasiticprotozoanEntamoebahistolyticawascrystallizedinthepresenceofsmallligandstogeneratesnapshotsofthelysine‐adenylateformation.Theresiduesinvolvedinlysineactivationarehighlyconservedandtheactivesiteclosesaroundthelysyl‐adenylate,asobservedinbacterialKRS.TheEntamoebaEMAPII‐likepolypeptideisnotresolvedinthecrystals,butanotherEntamoeba‐specificinsertioncouldbemodeledasasmallhelixbundlethatmaycontributetotRNAbindingthroughinteractionwiththetRNAhinge...