Two Signal Recognition Particle Sequences Are Present in the Amino-Terminal Domain of the C-Tailed Protein SciP.

ABSTRACT: During their synthesis, the C-tailed membrane proteins expose the membrane-spanning segment late from the ribosome and consequently can insert into the membrane only posttranslationally. However, the C-tailed type 6 secretion system (T6SS) component SciP uses the bacterial signal recognition particle (SRP) system for membrane targeting, which operates cotranslationally. Analysis of possible sequence regions in the amino-terminal part of the protein revealed two candidates that were then tested for whether they function as SRP signal peptides. Both sequences were tested positive as synthetic peptides for binding to SRP. In addition, purified ribosomes with stalled nascent chains exposing either sequence were capable of binding to SRP and SRP-FtsY complexes with high affinity. Together, the

SUBMITTER: Pross E 

PROVIDER: S-EPMC7723959 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature