What types of proteins are mainly encoded by plastid genomes?
The plastome (cpDNA) mainly encodes: (1) components of the plastid gene expression machinery (RNA polymerase, ribosomal proteins, tRNAs, and rRNAs), (2) subunits of each major functional photosynthesis-related complex (e.g., RuBisCO, Photosystem I and II, the cytochrome b6f complex, NADPH dehydrogenase, and ATP …
Is RNA found in plastids?
Plastids possess two types of RNA polymerase: (i) one multi-subunit, plastid-encoded prokaryotic-type RNA polymerase (PEP), and (ii) two different single-subunit, nuclear-encoded phage-type RNA polymerase(s) (NEP) (Shiina et al., 2005; Liere et al., 2011; Börner et al., 2015).
How is RNA polymerase involved with gene expression?
RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, duyring the process of transcription. For example, all species require a mechanism by which transcription can be regulated in order to achieve spatial and temporal changes in gene expression.
What stops the RNA polymerase?
Abstract. Among transcription factors that bind to bacterial RNA polymerase (RNAP) and modulate its activity, a number of small molecules irreversibly inhibit RNAP thereby causing cell death.
What are plastid genomes?
Most studied plastid genomes are circular-mapping molecules consisting of two inverted repeats (IR), a large single copy region (LSC) and a small single copy region (SSC); note that many red algae have lost one of the IRs. Plastid genomes often have ~100 genes and are 120 kbp to 200 kbp in size.
Do all plastids have DNA?
1.2 Plastid genome and nuclear-encoded plastid genes Chloroplasts and also other plastids of plant cells contain their own genomes as multicopies of a circular double-stranded DNA.
What is plastids and the types of plastids?
Answer: Plastids are double-membrane organelles that are found in the cells of plants and algae. Plastids are responsible for the manufacturing and storing of food. These often contain pigments that are used in photosynthesis and different types of pigments that can change the colour of the cell.
Where plastids are found?
Primary plastids are found in most algae and plants, and secondary, more-complex plastids are typically found in plankton, such as diatoms and dinoflagellates.
What are the three types of RNA polymerase?
All eukaryotes have three different RNA polymerases (RNAPs) which transcribe different types of genes. RNA polymerase I transcribes rRNA genes, RNA polymerase II transcribes mRNA, miRNA, snRNA, and snoRNA genes, and RNA polymerase III transcribes tRNA and 5S rRNA genes.
Is RNA polymerase involved in translation?
The factor controlling these processes is RNA polymerase in transcription and ribosomes in translation. In transcription, this polymerase moves over the template strand of DNA, while in translation, the ribosome-tRNA complex moves over the mRNA strand.
Where is RNA polymerase 3 found?
RNA polymerase III is also located in the nucleus. This polymerase transcribes a variety of structural RNAs that includes the 5S pre-rRNA, transfer pre-RNAs (pre-tRNAs), and small nuclear pre-RNAs.
What 3 things does RNA polymerase do?
RNA polymerases transcribe the information in DNA into RNA molecules that have a variety of functions, including messenger RNA, transfer RNA, ribosomal RNA (for protein synthesis), ribozymes (for catalysis), and microRNA (for regulation of gene expression).