5m6s

From Proteopedia

folding intermediate of spectrin R16

5m6s, resolution 4.80Å

Structural highlights

5m6s is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 4.8Å
Experimental data:	Check to display Experimental Data
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

LPTN_ECOLI Required for tryptophan-regulated expression of the tna operon. In the presence of free L-Trp release of this nascent peptide by release factor 2 is inhibited and the ribosome stalls with the last amino acid in the P site and a UGA stop codon in the A site. This prevent transcripiton termination factor Rho binding, and thus allows transcription and translation of TnaA and TnaB.SPTN1_CHICK Morphologically, spectrin-like proteins appear to be related to spectrin, showing a flexible rod-like structure. They can bind actin but seem to differ in their calmodulin-binding activity. In nonerythroid tissues, spectrins, in association with some other proteins, may play an important role in membrane organization.

Publication Abstract from PubMed

How do the key features of protein folding, elucidated from studies on native, isolated proteins, manifest in cotranslational folding on the ribosome? Using a well-characterized family of homologous alpha-helical proteins with a range of biophysical properties, we show that spectrin domains can fold vectorially on the ribosome and may do so via a pathway different from that of the isolated domain. We use cryo-EM to reveal a folded or partially folded structure, formed in the vestibule of the ribosome. Our results reveal that it is not possible to predict which domains will fold within the ribosome on the basis of the folding behavior of isolated domains; instead, we propose that a complex balance of the rate of folding, the rate of translation and the lifetime of folded or partly folded states will determine whether folding occurs cotranslationally on actively translating ribosomes.

Cotranslational folding of spectrin domains via partially structured states.,Nilsson OB, Nickson AA, Hollins JJ, Wickles S, Steward A, Beckmann R, von Heijne G, Clarke J Nat Struct Mol Biol. 2017 Jan 23. doi: 10.1038/nsmb.3355. PMID:28112730^[1]

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

References

↑ Nilsson OB, Nickson AA, Hollins JJ, Wickles S, Steward A, Beckmann R, von Heijne G, Clarke J. Cotranslational folding of spectrin domains via partially structured states. Nat Struct Mol Biol. 2017 Jan 23. doi: 10.1038/nsmb.3355. PMID:28112730 doi:http://dx.doi.org/10.1038/nsmb.3355