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Proteins and Proteomics
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
TBP is a general TF that binds specifically to a DNA sequence called the TATA box. This DNA sequence is found about 30 base pairs upstream of the transcription start site in some eukaryotic gene promoters. TBP, along with a variety of TBP-associated factors, make up the TFIID, a general TF that in turn makes up part of the RNA polymerase II preinitiation complex. As one of the few proteins in the preinitiation complex that binds DNA in a sequence-specific manner, it helps position RNA polymerase II over the transcription start site of the gene. However, it is estimated that only 10%–20% of human promoters have TATA boxes. Therefore, TBP is probably not the only protein involved in positioning RNA polymerase II. TBP is involved in DNA melting (double strand separation) by bending the DNA by 80° (the AT-rich sequence to which it binds facilitates easy melting). The TBP is an unusual protein in that it binds the minor groove using a β sheet.
Proteins and proteomics
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2018
The TBP is a general transcription factor that binds specifically to a DNA sequence called the TATA box. This DNA sequence has found about 30 base pairs upstream of the transcription start site in some eukaryotic gene promoters. TBP, along with a variety of TBP-associated factors, make up the TFIID, a general transcription factor that in turn makes up part of the RNA polymerase II preinitiation complex. As one of the few proteins in the preinitiation complex that binds DNA in a sequence-specific manner, it helps position RNA polymerase II over the transcription start site of the gene. However, it is estimated that only 10%–20% of human promoters have TATA boxes. Therefore, TBP is probably not the only protein involved in positioning RNA polymerase II. TBP is involved in DNA melting (dou-ble strand separation) by bending the DNA by 80° (the AT-rich sequence to which it binds facilitates easy melting). The TBP is an unusual protein since it binds the minor groove using a β sheet.
General Introductory Topics
Published in Vadim Backman, Adam Wax, Hao F. Zhang, A Laboratory Manual in Biophotonics, 2018
Vadim Backman, Adam Wax, Hao F. Zhang
In the pre-initiation of transcription, a pre-initiation complex contains the following: a core promoter sequence, transcription factors, DNA helicase, RNA polymerase, and various activators and repressors. Essentially, the promoter is the DNA site that allows transcription to start; transcription factors then significantly enhance the rate of transcription; the DNA helicase dehybridizes the DNA double strand, and the RNA polymerase reads out the gene sequence and helps produce mRNA, while activators, repressors, coactivators, and corepressors modulate the process.
It's not just about protein turnover: the role of ribosomal biogenesis and satellite cells in the regulation of skeletal muscle hypertrophy
Published in European Journal of Sport Science, 2019
Matthew Stewart Brook, Daniel James Wilkinson, Ken Smith, Philip James Atherton
Protein synthesis is the process by which ribosomes create polypeptide chains through linking amino acids together in a specific order according to mRNA. As such, rates of protein synthesis can be modulated by the rate of mRNA translation, known as “translational efficiency”. A primary control point regulating translational efficiency and therefore protein synthesis in the majority of eukaryotic cells is by cap dependent translation. This involves the assembly of many eukaryotic initiation factors (eIF's) to form a preinitiation complex (PIC) that interacts with the 5′ end of an mRNA to instigate protein synthesis (for more detail readers are directed to [Jackson, Hellen, & Pestova, 2010]). However, with protein synthesis being an energy demanding processes (e.g. through peptide bonding) it is unsurprising that there is myriad of regulating signaling cascades, many of which culminate on the mammalian target of rapamycin (mTOR), that integrates signals such as exercise, AA availability and energy status to coordinate cellular metabolism (Goodman et al., 2011). Some of the best understood targets of mTOR are those directly involved in cap-dependent translation, including P70S6K1, 4E-BP1, and RPS6 that can enhance translation initiation and efficiency in the absence of ribosomal biogenesis (Chesley, MacDougall, Tarnopolsky, Atkinson, & Smith, 1992).