Polyprotein
Proteins (/ˈproʊˌtiːnz/ or /ˈproʊti.ɨnz/) are large biological molecules consisting of one or more chains of amino acids. Proteins perform a vast array of functions within living organisms, including catalyzing metabolic reactions, replicating DNA, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in folding of the protein into a specific three-dimensional structure that determines its activity.
A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the genetic code specifies 20 standard amino acids; however, in certain organisms the genetic code can include selenocysteine and—in certain archaeapyrrolysine. Shortly after or even during synthesis, the residues in a protein are often chemically modified by posttranslational modification, which alters the physical and chemical properties, folding, stability, activity, and ultimately, the function of the proteins. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors. Proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes.
Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyze biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. Proteins are also necessary in animals' diets, since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism.
Proteins may be purified from other cellular components using a variety of techniques such as ultracentrifugation, precipitation, electrophoresis, and chromatography; the advent of genetic engineering has made possible a number of methods to facilitate purification. Methods commonly used to study protein structure and function include immunohistochemistry, site-directed mutagenesis, nuclear magnetic resonance and mass spectrometry.

This is an excerpt from the article Polyprotein from the Wikipedia free encyclopedia. A list of authors is available at Wikipedia.
The article Polyprotein at en.wikipedia.org was accessed 183 times in the last 30 days. (as of: 06/11/2013)
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Polyprotein - Medical Definition and More from Merriam-Webster
poly·pro·tein. noun \ˌpäl-i-ˈprō-ˌtēn, -ˈprōt-ē-ən\. Definition of Polyprotein. : a large protein that is cleaved into separate smaller proteins with different ...
www.merriam-webster.com/medical/polyprotein
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Polyprotein - definition from Biology-Online.org
Definition and other additional information on Polyprotein from Biology-Online. org dictionary.
www.biology-online.org/dictionary/Polyprotein
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polyprotein - Wiktionary
Polyprotein (plural Polyproteins). (biochemistry) Any protein (especially ones produced by viruses) that cleave to produce a number of polypeptides, some of ...
en.wiktionary.org/wiki/polyprotein
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Gag polyprotein - Proteopedia, life in 3D
The mature CAN domain of the HIV-1 Gag283 Polyprotein (1gwp), is a protein involved in formation of the capsid core particle. The structure of the CAN domain ...
proteopedia.org/wiki/index.php/Gag_polyprotein
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Analysis of the aphthovirus 2A/2B polyprotein'cleavage'mechanism ...
J Gen Virol. 2001 May;82(Pt 5):1013-25. Analysis of the aphthovirus 2A/2B Polyprotein 'cleavage' mechanism indicates not a proteolytic reaction, but a novel ...
www.ncbi.nlm.nih.gov/pubmed/11297676
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E unum pluribus: multiple proteins from a self-processing polyprotein.
Trends Biotechnol. 2006 Feb;24(2):68-75. Epub 2005 Dec 27. E unum pluribus: multiple proteins from a self-processing Polyprotein. de Felipe P, Luke GA, ...
www.ncbi.nlm.nih.gov/pubmed/16380176
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Polyprotein processing protease of African swine fever virus ...
J Virol. 2003 Apr;77(7):4444-8. Polyprotein processing protease of African swine fever virus: purification and biochemical characterization. Rubio D, Alejo A, ...
www.ncbi.nlm.nih.gov/pubmed/12634404
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Pol polyprotein - AKV murine leukemia virus - UniProt
Function. During replicative cycle of retroviruses, the reverse-transcribed viral DNA is integrated into the host chromosome by the viral integrase enzyme. RNase ...
www.uniprot.org/uniprot/P03356
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Gag-Pol polyprotein - Human immunodeficiency virus type 1 group ...
Function. Gag-Pol Polyprotein and Gag Polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag -Pol ...
www.uniprot.org/uniprot/P03366
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Gag polyprotein - Human immunodeficiency virus type 1 group M ...
Function. Matrix protein p17 targets Gag and Gag-Pol Polyproteins to the plasma membrane via a multipartite membrane binding signal, that includes its ...
www.uniprot.org/uniprot/O93182
Search results for "Polyprotein"
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Polyprotein in science
Gag polyprotein - Proteopedia, life in 3D
Students: Zheng Wang, Allison Tegge, Xin Deng: Advisors: Jianlin Cheng, PhD, Department of ...
Polyprotein FP9 PP and MVA PP | www.euvaccine.eu
Portfolio › Projects no longer active › Polyprotein FP9 PP and MVA PP ... In 2004 two contracts were signed with the University of Oxford, both sponsored by ...
Altering an Artificial Gagpolnef Polyprotein and Mode of ENV Co ...
Affiliation: Institute of Medical Microbiology, University of Regensburg, ... HIV-1 candidate vaccines expressing an artificial Polyprotein comprising Gag, Pol and ...
PLOS ONE: Altering an Artificial Gagpolnef Polyprotein and Mode of ...
Affiliation: Institute of Medical Microbiology, University of Regensburg, Regensburg, Germany. X. Jens Wild equal contributor,. equal contributor Contributed ...
Sporozoite Challenge of Polyprotein Vaccinees - Full Text View ...
Sep 10, 2006 ... Sporozoite Challenge of Polyprotein Vaccinees. This study ... University of Oxford ... Biological: MVA-PP (Modified Virus Ankara Polyprotein) ...
A novel cleavage site within the potato leafroll virus P1 polyprotein
A novel cleavage site within the potato leafroll virus P1 Polyprotein ... ↵†Present address: Gatty Marine Laboratory, School of Biology, University of St Andrews, ...
Trends in Microbiology - HIV Gag polyprotein: processing and early ...
Dec 24, 2012 ... Over the past several decades, extensive research into the Gag Polyprotein, the main structural protein of HIV-1 and all other retroviruses, has ...
E unum pluribus: multiple proteins from a self-processing polyprotein.
E unum pluribus: multiple proteins from a self-processing Polyprotein. ... Sciences , School of Biology, Biomolecular Sciences Building, University of St Andrews, ...
Overview of hepatitis C virus genome structure, polyprotein ...
Overview of hepatitis C virus genome structure, Polyprotein processing, and protein ... Department of Molecular Microbiology, Washington University School of ...
Structural and functional insights into alphavirus polyprotein ...
Sep 25, 2012... Department of Chemistry and Chemical Biology, Rutgers University, ... Processing of the Polyprotein occurs in a highly regulated manner, ...
Books on the term Polyprotein
Domain Dissection of Large Polyproteins as a Tool for ...
Domain Dissection of Large Polyproteins as a Tool for ...
Todd William Geders, 2007
As cellular concentrations of the P123 and p230 Polyproteins increase during infection, the protease domain of nsP2 cleaves in trans nsP1 from the P123 Polyprotein to yield nsP1 and P23 (Figure 1.11). Late in infection, P23 is cleaved in trans ...
Protein Structure by Distance Analysis
Protein Structure by Distance Analysis
Henrik G. Bohr, Søren Brunak, 1994
Figure 3: Stereo pair drawing of a Polyprotein constructed from 18 protein modules (Table 2). cannot be deduced from the Polyprotein conformation. The Polyprotein can be employed to challenge the predictive power of a force field in the ...
Bioinformatics and Functional Genomics
Bioinformatics and Functional Genomics
Jonathan Pevsner, 2013
2884 0.0 E 5 117003-63 l-POL H0181 Gag-P01 Polyprotein [PrlSDGag-Pol) [Col- Ito... 20576 0.0 52 903135? POL HVIBR Gag—Pol Polyprotein (PrlSOGag—Pol) [ Conta... m 0.0 s |P04587|POL HVIBS Gag—P01 Polyprotein (PrlSOGag-Pol) ...
Tick-Borne Diseases: Advances in Research and Treatment: 2011 ...
Tick-Borne Diseases: Advances in Research and Treatment: 2011 ...
2012
Researchers detail in 'African swine fever virus Polyprotein pp62 is essential for viral core development,' new data in life sciences. According to recent research from Cantoblanco, Spain, “One of the most characteristic features of African swine ...
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Blog posts on the term
Polyprotein
Virology Journal | Full text | Phylogenetic analyses of the polyprotein coding sequences of serotype O foot-and-mouth disease viruses in East Africa: evidence for interserotypic recombination
Foot-and-mouth disease (FMD) is endemic in East Africa with the majority of the reported outbreaks attributed to serotype O virus. In this study, phylogenetic analyses of the Polyprotein coding region of serotype O FMD viruses from Kenya and Uganda has been undertaken to infer evolutionary relationships and processes responsible for the generation and maintenance of diversity within this serotype. FMD virus RNA was obtained from six samples following virus isolation in cell culture and in one case by direct extraction from an oropharyngeal sample. Following RT-PCR, the single long open reading frame, encoding the Polyprotein, was sequenced.
www.virologyj.com/content/7/1/199
Abnormal processing of a recombinant feline leukemia virus envelope polyprotein and its interference with subgroup C virus infection | Natural Sciences Bibliography
Bechtel, Marta K.; Stallcup, Michael R.; Bedgood, Robert M.; Corey, Janis L.; Pandey, Rakesh; Roy Burman, Pradip, 1994: Abnormal processing of a recombinan...
scien.net/general/microscopy/abnormal-processing-of-a-recombinant-feline-leukemia-virus-envelope-polyprotein-and-its-interference-with-subgroup-c-virus-infection
"Domain dissection of large polyproteins as a tool for structure-functi" by Todd William Geders
Polyproteins are large proteins with multiple functional domains. Many are difficult to study biochemically due to their size and multiple enzymatic functions. Here I present examples of a domain dissection methodology used to excise functional domains from larger Polyproteins for structure-function analysis. Examples are given from bacterial polyketide synthases and plus-stranded RNA viral replicases. The first domain dissection example is of the loading domain of CurA, a 2311 amino acid Polyprotein involved in polyketide chain initiation of curacin A biosynthesis. One domain excised from CurA, termed GNATL, was demonstrated to possess an unprecedented decarboxylase and S-acyltransferase activity. The GNATL-domain structure was determined and revealed a GCN5-related N-acetyltransferase (GNAT) fold. The structure, in conjunction with functional analysis and site-directed mutagenesis, identified two catalytically important active site residues, Thr355 and His389. A new GNAT-like strategy for polyketide chain initiation was identified and proposed. The second domain dissection example is of the ECH2 domain of CurF, a 3195 amino acid Polyprotein involved in curacin A biosynthesis. The N-terminal ECH 2 domain of CurF is a decarboxylase and the last component of a five protein HMG-CoA synthase-containing "HCS cassette" that is used to introduce a β-branch into polyketides. The structure of the ECH2 domain of CurF was determined, revealed a crotonase fold, and identified a number of potential active site residues. Modeling of the substrate into the active site aided the selection of three residues for site-directed mutagenesis. In a coupled ECH1/ECH2 dehydration/decarboxylase assay, two catalytically important residues, His240 and Lys 86, were identified and their roles in decarboxylation proposed. The structure-function analysis of CurF ECH2 has provided insight into how β-branching is controlled in "HCS cassettes". The third domain dissection example is from the alphavirus nsP2 and nsP3 components of the ∼2500 amino acid nonstructural Polyprotein genome replicase. Here I present results from high-throughput domain dissection experiments designed to obtain soluble protein for structure-function studies. The protease domain of Sindbis nsP2 was produced and demonstrated to possess site-specific protease activity in two in vitro protease assays, an unexpected RNA binding activity, and a previously unrecognized methyltransferase-like subdomain. ^
docs.lib.purdue.edu/dissertations/AAI3307450/
Flaviviruses: Translation and Processing of the Virus Polyprotein
www.horizonpress.com/blogger/2009/09/flaviviruses-translation-and-processing.html
Evolutionary Trace Analysis of the Precursor Polyprotein Encoded by the Genome Segment a of Infectious Bursal Disease Virus » Agricultural Science Paper
]]> Title Evolutionary Trace Analysis of the Precursor Polyprotein Encoded by the Genome Segment a of Infectious Bursal Disease Virus Abstract Divergence of virus virulence has been one of the focuses in the animal virology, specifically manystudies have attempted to elucidate the molecular basis of virulence divergence of infectious bursaldisease virus. Previous studies have shown that the precursor Polyprotein where VP2is located has ahigher mutation frequency than other regions of the IBDV genome, even it can be argued that thisregion can be used to distinguish the variant strains of IBDV, such as variant, classic and very virulentstrains.
www.agrpaper.com/evolutionary-trace-analysis-of-the-precursor-polyprotein-encoded-by-the-genome-segment-a-of-infectious-bursal-disease-virus-3.htm
Figure options The HIV structural polyprotein Gag is | Online Peptides Guide
Posted on April 23, 2013 by admin.
www.coagulation-factor-ii-peptide.com/figure-options-the-hiv-structural-polyprotein-gag-is.html
Retrovirology | Full text | Identification of the protease cleavage sites in a reconstituted Gag polyprotein of an HERV-K(HML-2) element
The human genome harbors several largely preserved HERV-K(HML-2) elements. Although this retroviral family comes closest of all known HERVs to producing replication competent virions, mutations acquired during their chromosomal residence have rendered them incapable of expressing infectious particles. This also holds true for the HERV-K113 element that has conserved open reading frames (ORFs) for all its proteins in addition to a functional LTR promoter. Uncertainty concerning the localization and impact of post-insertional mutations has greatly hampered the functional characterization of these ancient retroviruses and their proteins. However, analogous to other betaretroviruses, it is known that HERV-K(HML-2) virions undergo a maturation process during or shortly after release from the host cell. During this process, the subdomains of the Gag Polyproteins are released by proteolytic cleavage, although the nature of the mature HERV-K(HML-2) Gag proteins and the exact position of the cleavage sites have until now remained unknown.
www.retrovirology.com/content/8/1/30
Polyproteins (Molecular Biology)
Large precursor proteins encoding one or more active peptides or polypeptide chains are referred to as Polyproteins. Polyproteins are synthesized on ribosomes in the normal method of protein biosynthesis, transported into the lumen of the rough endoplasmic reticulum (ER) and
what-when-how.com/molecular-biology/polyproteins-molecular-biology/
Uutta viruksista: Antiviral strategy targeting Gag polyprotein
http://www. drexelmed.
virustietoutta.blogspot.com/2011/12/antiviral-strategy-targeting-gag.html
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