Mechanical force releases nascent chain–mediated ribosome arrest in vitro and in vivo

摘要: Protein synthesis rates can affect gene expression and the folding activity of translation product. Interactions between nascent polypeptide ribosome exit tunnel represent one mode regulating rates. The SecM protein arrests its own translation, release arrest at translocon has been proposed to occur by mechanical force. Using optical tweezers, we demonstrate that SecM-stalled ribosomes indeed be rescued force alone needed stalling generated in vivo a chain near exit. We formulate kinetic model describing how regulate during folding, tuning structure acquisition polypeptide.