Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Apr;155(4):1520-32.
doi: 10.1104/pp.110.171231. Epub 2011 Feb 23.

Expression of plastid genes: organelle-specific elaborations on a prokaryotic scaffold

Alice Barkan  1
Affiliations

Expression of plastid genes: organelle-specific elaborations on a prokaryotic scaffold

Alice Barkan. Plant Physiol. 2011 Apr.
No abstract available

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Sequestration of a segment of single-stranded RNA by a long PPR tract may account for many functions attributed to PPR proteins. This is exemplified by PPR10, which stabilizes specific processed RNA termini (A) and enhances translation (B) by sequestering the same RNA segment (Pfalz et al., 2009; Prikryl et al., 2011). Analogous interactions could influence RNA processing, stability, and translation in other ways. A, Site-specific barrier activity of PPR10 defines processed RNA termini. The processed RNA termini derived from polycistronic transcripts spanning atpI and atpH are shown at the top. PPR10 binds this intergenic region and promotes the accumulation of processed RNAs by blocking exoribonucleases intruding from either direction. The processed atpI and atpH transcripts derive from different precursor molecules. B, Site-specific RNA-remodeling activity of PPR10 enhances translation. The atpH ribosome-binding site (RBS) is sequestered in a duplex with a portion of the PPR10-binding site. PPR10 binding frees the atpH ribosome-binding site for translation (Pfalz et al., 2009; Prikryl et al., 2011).
Figure 2.
Figure 2.
Model for expression of the chloroplast psbB gene cluster. The psbB gene cluster spans five genes and generates approximately 20 processed transcripts via intercistronic processing and the splicing of group II introns in the petB and petD genes (Barkan, 1988; Westhoff and Herrmann, 1988). The diagram shows a subset of the processed transcripts. Splicing factors for the petB and petD introns are indicated above, with their organelle-specific RNA-binding domains specified in parentheses (for review, see de Longevialle et al., 2010; Watkins et al., 2011). The position of a bound PPR-like protein defines the positions of processed RNA termini in each intercistronic region by blocking exoribonucleases; genetic data implicate HCF107, HCF152, and CRP1 in the indicated events (Barkan et al., 1994; Felder et al., 2001; Meierhoff et al., 2003), but these interactions have not been confirmed biochemically. The endonucleases RNAse E and RNAse J are posited to cleave rather nonspecifically at unstructured AU-rich regions to provide exonuclease access to internal RNA regions. A generic version of this model was presented previously, based on the effects of PPR10 on two other transcription units (Pfalz et al., 2009).
See this image and copyright information in PMC

References

    1. Adam Z. (2007) Protein stability and degradation in plastids. Bock R, , Cell and Molecular Biology of Plastids. Springer-Verlag, Heidelberg, pp 315–338
    1. Adhin MR, van Duin J. (1990) Scanning model for translational reinitiation in eubacteria. J Mol Biol 213: 811–818 - PubMed
    1. Allison LA, Simon LD, Maliga P. (1996) Deletion of rpoB reveals a second distinct transcription system in plastids of higher plants. EMBO J 15: 2802–2809 - PMC - PubMed
    1. Amann K, Lezhneva L, Wanner G, Herrmann RG, Meurer J. (2004) ACCUMULATION OF PHOTOSYSTEM ONE1, a member of a novel gene family, is required for accumulation of [4Fe-4S] cluster-containing chloroplast complexes and antenna proteins. Plant Cell 16: 3084–3097 - PMC - PubMed
    1. Barkan A. (1988) Proteins encoded by a complex chloroplast transcription unit are each translated from both monocistronic and polycistronic mRNAs. EMBO J 7: 2637–2644 - PMC - PubMed

Publication types

LinkOut - more resources