Glycophorin A (GpA) is a protein found in the human membrane red blood cell. The GpA protein is obtained from the gene called glycophorin A (MNS blood group) or GpA. The GpA gene bears the antigenic determinants for the MN and Ss blood groups, and 40 related variants of the Miltenberger complex and several isoforms of Sta1. There are two classes of membrane glycoproteins, asialo and sialoglycoproteins (glycophorins). These glycoproteins are determined by the presence of sialic acid which is the negative charge on cell surface. GpA is the primary sialoglycoprotein of human erythrocyte membranes that forms noncovalent dimers by sequence-specific, reversible association of its single hydrophobic membrane-spanning domain2. The glycophorin consists of four human genes GpA, GpB, GpC, and GpE that encode glycophorin proteins. GpA is characterized within the family of glycophorin under the glycophorin superfamily. GpA protein is found on the long arm of chromosome 4. Figure 1: Dimeric transmembrane domain of Glycophorin A (PDB: 1AFO)3. The sequence of the transmembrane GpA protein show that there are 80 amino acid residues. The sequence also shows 54 out of 80 residues are hydrophobic. The secondary structure of GpA protein reveals that these residues interact to form two same monomers, homodimer. Each of the dimer is an alpha helix containing 40 amino acids. According to RCSB protein databank, the homodimer is asymmetric as shown in figure 1. Alpha helices of GpA protein span at -400 to position an interface that lack hydrogen bonding within the monomers. The arrangement of the interface provides the physical basis for the interactions between the two helices. Two glycines are observed to help in the backbone-backbone contact of t... ... middle of paper ... ...hydrophilic. The sequence determine that the structure is two alpha helices embedded in the bilayer of the membrane while the N- and C-terminal are on the outside and inside of the membrane interacting with the hydrophilic environment. The structure of this membrane protein has significant biological functions such as virus binding, cell-surface antigenicity, cell-cell recognition, cell-cell communication, cellular transformation, transport, energy transduction4. Works Cited 1. "GYPA." Genetics Home Reference. National Library of Medicine (US), 2014. Accessed: 16 Feb 2014. . 2. MacKenzie, K., J. Prestegard, and D. Engelman."A Transmembrane Helix Dimer: Structure and Implications." Science. 276. (1997): 131-3. 3. http://www.rcsb.org/pdb/ 4. Tayyab, S., and M. Qasim. "Biochemistry and roles of glycophorin A." 16.2 (1988): 63-6.
The sequence of BRCA1 protein shows that there are quite a few of cysteine residues. These cysteine residues form disulfide bonds which help stabilize the secondary structure of the protein. The secondary structure of BRCA1 protein indicates that there are alpha helices and beta turns which are connected by loops and turns. The 3D structure of BRCA1/BARD1 RING-domain heterodimer is shown in figure 1.
Cytomegalovirus (CMV) is the most common virus in the United States that can infect almost any individual. Cytomegalovirus is also referred to as Herpesvirus-5, which belongs to a branch of Herpesviridae family. Herpesviridae has a spherical shape that contains four significant elements that are important to the viron. The four elements are the core, tegument, capsid and the envelope. Alphaherpesvirinae, Betaherpesvirinae and Gammaherpesvirinae are three subfamilies which belong to Herpesviridae. Cytomegalovirus belongs to the Betaherpesvirinae family, which also include Muromegalovirus and Roseolovirus. The Alphaherpesvirinae subfamily includes Simplexvirus, Varicellovirus, Mardivirus and Iltovirus genera. The Gammaherpesvirinae subfamily contains Lymphocryptovirus and Rhadinovirus genera. The diameter size of the virus is based on each specific family; however, the core remains the same throughout the species, which contains single layer of double stranded DNA tightly condensed in the capsid. In the tegument component, there are 30 or more viral proteins that are shapeless that encompass the capsid. Out of the four major components, the tegument has the most poorly defined structure. On the other hand, the capsid is a well-defined structure that is an icosahedron, which is composed of 162 capsomeres, 12 of which are pentons and 150 are hexons (1). Last but not least, the liquid envelope surrounds the tegument with approximately 10 glycoprotein and cellular proteins. Each subfamily under the herpesviriade has its own arrangement between the liquid envelop and the tegument layer.
The size of the terminal deletion may vary from a subtle 1.4Mb to a classic 30Mb [5]. Earlier genotype-phenotype correlation studies reveal that the main characteristic feature of WHS - the ‘Greek warrior helmet face’, is caused due to the hemizygosity of the WHSC1 gene located in the WHS critical region (WHSCR).[5] Various other genes are also located in the WHSCR which are responsible for most other phenotypic features. More precisely, the Wolf-Hirschhorn syndrome critical region (WHSCR) is located at 4p16.3 region. Approximately 25% of the patients with WHS deletion in this region are not detectable by cytogenetic karyotyping [6]. Hence, FISH has to be performed.
Blood types can be categorized in many different ways. Karl Landsteiner categorized “the first three blood groups…[as] A, B and C (subsequently renamed O from the German word “ohne” which means “without”)” (Franchini 1545). Each of these blood groups also have unique properties that give the blood an inability to mix with other blood types. For example, Landsteiner has found out that type-A red blood cells contains an A-antigen and anti-B in its serum (Franchini 1545). Type A blood contains the monosaccharides N-acetylglucosamine, galactose, fructose, and “a N-acetylgalactosamine attached to galactose” (Timberlake 556).The A-antigen is used as an identifier for the body to determine whether something in the bodies system belongs or ...
CP consists of a single domain with high α-helical content [4]. The N-terminal part this domain is surface exposed whereas the C-terminal region buried in the virion. Several experiments indicate the CP is an O-glycoprotein. Equal amounts of galactose and fructose residues are O-linked to an acetylated serine residue at the N-terminal region [2]. This mediates the formation of a structured...
James E. Rothman was born on the 3rd of November 1950 in Haverhill, Massachusetts. Rothman is a professor at Yale School of Medicine for the Cell Biology department. Rothman was given the Nobel Prize for vesicle trafficking in the human body. In the late 1980s and 1990s Rothman began to study the transportation of mammalian cells. He discovered that there was “a protein complex allows vesicles to dock and fuse with their target membranes” (Altman). After his investigation he determined that the proteins on the vesicles and target membranes bind together completely. When Rothman was conducting his investigation he noticed the combination of the proteins which led him to conduce that the relation to allow the cell to reach to a particular location at a particular time was beyond belief.
2. "Rett syndrome." Holly A. Ishmael, MS, CGC. The Gale Encyclopedia of Genetic Disorders. Ed. Laurie Fundukian. 3rd ed. Detroit: Gale, 2010. 2 vols.
The virus is primarily spherical shaped and roughly 200nm in size, surrounded by a host-cell derived membrane. Its genome is minus-sense single-stranded RNA 16-18 kb in length. It contains matrix protein inside the envelope, hemagglutinin and neuraminidase, fusion protein, nucleocapsid protein, and L and P proteins to form the RNA polymerase. The host-cell receptors on the outside are hemagglutinin and neuraminidase. The virus is allowed to enter the cell when the hemagglutinin/ neuraminidase glycoproteins fuse with the sialic acid on the surface of the host cell, and the capsid enters the cytoplasm. The infected cells express the fusion protein from the virus, and this links the host cells together to create syncitia.
Lewis, Ricki, (2014), Human Genetics, 11th Edition, Chapter 12. Gene Mutation. [VitalSource Bookshelf Online]. Retrieved from
its original shape and shape. Within the phospholipid bi-layer there are proteins, and these. proteins are made up of polypeptide chains which are joined together. by hydrogen, hydrophobic and peptide bonds. Once the temperature has increased above 40°C the molecules vibrate so energetically that these bonds break easily and therefore create holes within the cell wall.
“This knowledge will help us design drugs that mimic the viral effects on these proteins to either activate a host’s immune response or shut it down,” said Dr. Michael Gale, associate ...
Myoglobin consist of single polypeptide chain that made up of 153 amino acid and ahs a size of 18 kDa. Its three-dimensional structure was first determined by X-ray crystallography by John Kendrew in 1957. Myoglobin is a typical globular protein in that it is a highly folded compact structure with most of the hydrophobic amino acid residues buried in the interior and many of the polar residues on the surface. X-ray crystallography revealed that the single polypeptide chain of myoglobin consist of entirely of eight (labelled A-H) alpha-helical. Within a hydrophobic crevice formed by the folding polypeptide chain is the heme prosthetic group. This nonopolypepetide unit is noncovalently bound to myoglobin and is essential for the biological activity of the protein.
"The Species of the Secondary Protein Structure. Virtual Chembook - Elmhurst College. Retrieved July 25, 2008, from http://www.cd http://www.elmhurst.edu/chm/vchembook/566secprotein.html Silk Road Foundation. n.d. - n.d. - n.d.
The "Genetic Screening" Genetic Screening. NDSU,. Web. The Web. The Web.
Figure 11. L7/L12 stalk. The 50S subunit rRNA is depicted in gray and the 50S r-proteins are shown in cyan. The L12 dimers are shown in red with its CTD, NTD and the hinge region. The L10 that provides flexibility is shown in blue while the L11 acting as a anchor is shown in yellow. The L7/L12 dimer stalk aids in delivery of the aa-tRNA ternary complex to the A-site of the ribosome (Diaconu et al.,