Correction for Ishii et al., Nascent chain-monitored remodeling of the Sec machinery for salinity adaptation of marine bacteria

MICROBIOLOGY Correction for “Nascent chain-monitored remodeling of the Sec machinery for salinity adaptation of marine bacteria,” by Eiji Ishii, Shinobu Chiba, Narimasa Hashimoto, Seiji Kojima, Michio Homma, Koreaki Ito, Yoshinori Akiyama, and Hiroyuki Mori, which appeared in issue 40, October 6, 2015, of Proc Natl Acad Sci USA (112:E5513–E5522; first published September 21, 2015; 10.1073/pnas.1513001112).

The authors note that Fig. 6 appeared incorrectly. The corrected figure and its legend appear below.

Fig. 6.

Regulatory importance of the vemP-secD2-secF2 operon arrangement. (A) Predicted secondary structure of mRNA at the vemP-secD2_VA intergenic region. The RNA sequence from the fifth last codon of vemP to the third codon of secD2_VA are shown with the secondary structure predicted by CentroidHomfold. The putative SD sequence and the start codon of secD2_VA are indicated by box and underline, respectively. The P site and the A site of the VemP-stalled ribosome (Fig. 4C) are shown schematically. To separate the VemP arrest point and the secondary structure-forming region, we inserted one or two copies of the 18 nucleotides encoding the last five amino acid residues of VemP followed by the termination codon, shown at the bottom. (B) Separation of the arrest point and the stem-loop-forming region impairs the regulation. E. coli cells carrying indicated vemP-secDF2_VA plasmids (with or without the insertion mutations shown in A) were induced with IPTG for 15 min at 37 °C and treated with (+) or without (−) 3 mM NaN₃ for 5 min. Cells were then pulse-labeled for 1 min. Cell extracts of equivalent radioactivities were subjected to anti-VemP (upper gel) and anti-V.SecD2 (lower gel) immunoprecipitation. In the upper gel, “p” indicates the signal peptide unprocessed form of VemP, which included the polypeptide part of the elongation arrested VemP, whereas “m” indicates the signal peptide-processed mature form. Relative intensities of V.SecD2 are shown in the bottom graph, taking the value of lane 1 as unity (n = 3). Gray and black bars represent results obtained without and with NaN₃ treatment, respectively. (C) The insertion mutations do not affect translation arrest of VemP. E. coli cells carrying pBAD24-Δss-vemP-V.secDF2 with or without the insertion mutations were induced with 0.02% arabinose for 1 h at 37 °C. The same amounts of proteins were separated by 10% wide-range gel electrophoresis, followed by immunodetection of VemP. (D) The secD2_VA-secF2_VA interval. The nucleotide sequence from the fourth last codon of secD2_VA to the fifth codon of secF2_VA is shown. The predicted SD sequence of secF2_VA is underlined.