Publisher Correction: Ancestral-sequence reconstruction unveils the structural basis of function in mammalian FMOs

Abstract

In the version of this article initially published, in Fig. 6b, top left panel, the β-sheet was labeled as a "Three-stranded bridging sheet. " The correct label is "Four-stranded bridging sheet. " The error has been corrected in the HTML and PDF versions of the article.

Combining ancestral reconstruction with folding-landscape simulations to engineer heterologous protein expression

“…4d) and, according to our working hypothesis, we do not expect its replacement with the corresponding ancestral sequence to improve the efficiency of heterologous folding. The experimental results on CPk- [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] thioredoxin conform to this expectation (Fig. 5c and d).…”

“…We followed procedures we have previously described in several publications [47][48][49]60 with small modifications. Briefly, genes encoding Candidatus Photodesmus katoptron thioredoxin (CPk) and the CPk chimeras (CPk and CPk [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52]) were synthesized with a His-tag at the Cterminal and codon optimized for expression in E. coli cells. Mutations required for the single-mutant CPk variants (L7V, D10E, S11N, L14Q, N15E, I17L, S18K, A19S, S20D, G21K, V22P, F70Y, G74S, V75I, S77T), the double-mutant S11N/G74S variant and the chimera involving the loop [70][71][72][73][74][75][76][77] were introduced using the QuikChange Lighting Site-Directed Mutagenesis kit (Agilent Technologies) and the sequences were confirmed by DNA sequencing.…”

“…Finally, a somewhat intriguing result of our extensive experimental study on the stability of CPk thioredoxin variants deserves some attention. While most of the variants show the expected stability enhancement, this is not the case with CPk- [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] thioredoxin. This modern/ancestral chimera involves 10 back-to-ancestor amino acid replacements in the longest a-helix of the thioredoxin structure, which is expected to fold early according to our statistical-mechanical calculations (Fig.…”

“…4). CPk- [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] thioredoxin displays a stability similar to that of the CPk thioredoxin background as shown by both the denaturation temperature values and the chemical denaturation profiles (Fig. S3).…”

“…Examples include: phosphate-binding protein 22 , periplasmic binding protein 23 , serum paraoxonase 24 , coagulation factor VIII 25 , titin 26 , haloalkane dehalogenases 27 , cytidine and adenine base editors 28 , diterpene cyclase 29 , rubisco 30 , endoglucanases 31 , L-amino acid oxidases 32 , laccases 33 , front-end D6-desaturases 34 and fatty acid photo-decarboxylases 35 . On a related note, recent studies on ancestral proteins have noted an improved capability to yield crystals suitable for X-ray structural determination 36,37 .…”