N-terminus

Abstract Bacteriorhodopsin is located in the plasma membrane of Halobacterium halobium, where it acts as a proton-pump, transporting protons out of the cell. Since its discovery in 1979, much research has been done on Bacteriorhodopsin and there have been many advancements in our knowledge. Firstly, on its structure and function and secondly, on the conformational changes it undergoes during retinal isomerisation. Introduction Bacteriorhodopsin is a globular protein, (Henderson, 1975) which…

There are many mechanisms of epigenetics, including such as de/acetylation and methylation of histones, hyper methylation of CpG islands and phosphorylation etc. Epigenetics can be both spontaneous and hereditary, with some forms of epigenetics, such as histone acetylation, being passed on through gametes. Some forms of epigenetics have large consequences, leading to some serious conditions e.g. Prader-Willi syndrome, whilst some can have longer term ramifications for future generations e.g.…

G-protein coupled receptors are found in eukaryotes, and are encoded by around 1-3% of the genes in the genome. In this essay I will discuss the general structure and model of activation of GPCRs, as well as how this model has been realised, through the study of bacteriorhodopsin, a homology model of GPCRs. There are many examples of GPCRs illustrating how GPCRs can have a wide range of cellular consequences and I will discuss how the activation of rhodopsin, sphingosine-1-phosphate receptors,…

binding sites for ATP as well as an ion, usually calcium or magnesium, deep in the cleft between subunits 2 and 4. (2) Figure 1. X-ray structure of rabbit muscle G-actin in complex with ATP and a Ca2+ ion. Included in this protein is a C-terminus and N-terminus with its four subunits displayed with different colors. The yellow ribbon represents the subdomain 4, blue represents subdomain 2, orange represents subdomain 3, and purple represents subdomain 1. ATP and Ca2+ also illustrated binding…

1. In a re-sequencing study to detect genetic variation that influences expression and inducibility of cytochrome P450 (CYP) enzymes, novel mutations are detected in the constitutive androstane receptor (CAR; NR1I3), a nuclear hormone receptor that acts as a transcription factor and controls the expression of CYPs including CYP34. Activation of CAR induces (increases) the expression of CYP enzymes. An alignment of the amino acid sequence of human, monkey, rat, and mouse CARs is indicated below.…

this family. The four extracellular domains are consisted of two types of modular units as shown in Figure 1, each one of those units is stabilised by one or two disulfide bonds. CD40 is made up of a single membrane spanning domain and expose the N-terminus of the protein to the exterior (type I membrane protein). Actually, CD40 is a hydrophobic protein with an acidic pI of 3.2. There are many recognition sites for the intermolecular proteins in the cytoplasmic domain of CD40 such…

Recent Insights into the Structure, Regulation, and Function of the V-ATPases Vacuolar ATPases are proton pumps that are dependent on ATP. They are involved with processes along the plasma membrane. The processes involved are membrane traffic, protein degradation, bone resorption, tumor cell invasion, and pH homeostasis. There has been a better understanding of the structure and mechanism of V-ATPases. Another thing brought to light, are the mechanisms that occur to regulate its activity in…

also known as acute myeloid leukemia 1 protein (AML1) or core-binding factor subunit alpha-2 (CBFA2) (10, 11). It is one of three RUNX proteins found in humans, all of which possess a highly conserved 128 amino acid Runt DNA-binding domain at the N-terminus. The Runt domain is important for binding with consensus sequence (PyGPyGGTPy) in DNA and with core binding factor subunit beta (CBF-β) (12). CBF-β heterodimerizes (13) with RUNX1, enhances RUNX1 affinity for the DNA by 10 fold (14) and…

adenosine are more resistant to depurination compared to deoxyadenosine and deoxyguanosine. Deoxyadenosine itself depurinates 1200 times faster than adenosine (York, 1981). Interestingly, N-acyl-protected purine nucleosides (particularly deoxyadenosine) are more prone to depurination than unprotected nucleosides. Among N-acyl-protected deoxyadenosines, protection at N6 with α-phenylcinnamoyl, naphthaloyl, 3-methoxy-4-phenoxybenzoyl, 9-fluorenylmethoxycarbonyl (FMOC), and tert-butylphenoxyacetyl…

promoters can transcribe an mrna that has to code a different amino terminus (Osborne, 2000). As a result, protein encoding information of the both isoforms are the same sequence because they are located in the same ORF (open reading frame) (Osborne, 2000). In terms of activating gene expression, the SREBP-1a has a large amount of acidic amino acids to make it become a significant transcriptional activation area inside the longer N-terminal region (Osborne, 2000). Yet the SREBP-1c is not as…