Abstract
Integral membrane proteins are assembled into the ER membrane via a continuous ribosome-translocon channel. The hydrophobicity and thickness of the core of the membrane bilayer leads to the expectation that transmembrane (TM) segments minimize the cost of harbouring polar polypeptide backbones by adopting a regular pattern of hydrogen bonds to form α-helices before integration. Co-translational folding of nascent chains into an α-helical conformation in the ribosomal tunnel has been demonstrated previously, but the features governing this folding are not well understood. In particular, little is known about what features influence the propensity to acquire α-helical structure in the ribosome. Using in vitro translation of truncated nascent chains trapped within the ribosome tunnel and molecular dynamics simulations, we show that folding in the ribosome is attained for TM helices but not for soluble helices, presumably facilitating SRP (signal recognition particle) recognition and/or a favourable conformation for membrane integration upon translocon entry.
| Original language | English |
|---|---|
| Article number | 5246 |
| Journal | Nature Communications |
| Volume | 9 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Dec 2018 |
ASJC Scopus subject areas
- Chemistry(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)
Cite this
Transmembrane but not soluble helices fold inside the ribosome tunnel. / Bañó-Polo, Manuel; Baeza-Delgado, Carlos; Tamborero, Silvia; Hazel, Anthony; Grau, Brayan; Nilsson, Ing Marie; Whitley, Paul; Gumbart, James C.; von Heijne, Gunnar; Mingarro, Ismael.
In: Nature Communications, Vol. 9, No. 1, 5246, 01.12.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transmembrane but not soluble helices fold inside the ribosome tunnel
AU - Bañó-Polo, Manuel
AU - Baeza-Delgado, Carlos
AU - Tamborero, Silvia
AU - Hazel, Anthony
AU - Grau, Brayan
AU - Nilsson, Ing Marie
AU - Whitley, Paul
AU - Gumbart, James C.
AU - von Heijne, Gunnar
AU - Mingarro, Ismael
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Integral membrane proteins are assembled into the ER membrane via a continuous ribosome-translocon channel. The hydrophobicity and thickness of the core of the membrane bilayer leads to the expectation that transmembrane (TM) segments minimize the cost of harbouring polar polypeptide backbones by adopting a regular pattern of hydrogen bonds to form α-helices before integration. Co-translational folding of nascent chains into an α-helical conformation in the ribosomal tunnel has been demonstrated previously, but the features governing this folding are not well understood. In particular, little is known about what features influence the propensity to acquire α-helical structure in the ribosome. Using in vitro translation of truncated nascent chains trapped within the ribosome tunnel and molecular dynamics simulations, we show that folding in the ribosome is attained for TM helices but not for soluble helices, presumably facilitating SRP (signal recognition particle) recognition and/or a favourable conformation for membrane integration upon translocon entry.
AB - Integral membrane proteins are assembled into the ER membrane via a continuous ribosome-translocon channel. The hydrophobicity and thickness of the core of the membrane bilayer leads to the expectation that transmembrane (TM) segments minimize the cost of harbouring polar polypeptide backbones by adopting a regular pattern of hydrogen bonds to form α-helices before integration. Co-translational folding of nascent chains into an α-helical conformation in the ribosomal tunnel has been demonstrated previously, but the features governing this folding are not well understood. In particular, little is known about what features influence the propensity to acquire α-helical structure in the ribosome. Using in vitro translation of truncated nascent chains trapped within the ribosome tunnel and molecular dynamics simulations, we show that folding in the ribosome is attained for TM helices but not for soluble helices, presumably facilitating SRP (signal recognition particle) recognition and/or a favourable conformation for membrane integration upon translocon entry.
UR - http://www.scopus.com/inward/record.url?scp=85058118180&partnerID=8YFLogxK
U2 - 10.1038/s41467-018-07554-7
DO - 10.1038/s41467-018-07554-7
M3 - Article
VL - 9
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 5246
ER -