G18secL03Tpc4: Difference between revisions
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is one of the major [http://en.wikipedia.org/wiki/Antigen antigens] on the surface of the [http://en.wikipedia.org/wiki/Lyme_disease Lyme disease] [http://en.wikipedia.org/wiki/Spirochaete spirochete], [http://en.wikipedia.org/wiki/Borrelia_burgdorferi ''Borrelia burgdorferi''], along with other outer surface proteins A and B ([http://www.proteopedia.org/wiki/index.php/OspA OspA] and [http://www.proteopedia.org/wiki/index.php/User:Marvin_O%27Neal/Antibody_OspA_and_OspB OspB], respectively). It greatly differs from OspA and OspB in both structure and function. The uniqueness of OspC is that it comes into play when the pathogen is being transmitted to humans or other mammals.OspC is critical for survival in or transmission to the tick or mammalian host.<ref>PMID:11169111</ref> OspC is being produced by ''Borrelia burgdorferi'' during a very short time interval when infected ticks start feeding, but its synthesis is known to slow down greatly after transmission to a mammalian host. Interestingly, when an infested tick engorges, ''B. burgdorferi'' within the gut multiply and downregulate ospA. At the same time, the spirochetes start producing OspC in the feeding gut and continue to produce OspC throughout the transmission process and during the establishment of early vertebrate infection. This pattern of expression suggests that OspC may serve a function in the tick, possibly facilitating the migration of the spirochete from the vector gut to the salivary glands during transmission. After transmission from the tick, OspC may also play a role in colonization of host tissues.<ref>PMID:14722614</ref> It was demonstrated that those spirochetes that lack OspC are capable to replicate inside and migrate to the salivary glands of the tick vector but do not infect mammals. <ref name="Kum">D. Kumaran1, S. Eswaramoorthy1, B.J. Luft2, S. Koide3, J.J. Dunn1, C.L. Lawson1,4 and S. Swaminathan1. Crystal structure of outer surface protein C (OspC) from the Lyme disease spirochete, Borrelia burgdorferi.The EMBO Journal (2001) 20, 971 - 978 [http://dx.doi.org/DOI:10.1093/emboj/20.5.971]</ref> Without OspC the spirochetes are believed to be unable to adapt to the environment inside the host. Therefore, OspC is believed to determine [http://en.wikipedia.org/wiki/Virulence virulence] of the spirochete to mammals, including humans. | is one of the major [http://en.wikipedia.org/wiki/Antigen antigens] on the surface of the [http://en.wikipedia.org/wiki/Lyme_disease Lyme disease] [http://en.wikipedia.org/wiki/Spirochaete spirochete], [http://en.wikipedia.org/wiki/Borrelia_burgdorferi ''Borrelia burgdorferi''], along with other outer surface proteins A and B ([http://www.proteopedia.org/wiki/index.php/OspA OspA] and [http://www.proteopedia.org/wiki/index.php/User:Marvin_O%27Neal/Antibody_OspA_and_OspB OspB], respectively). It greatly differs from OspA and OspB in both structure and function. The uniqueness of OspC is that it comes into play when the pathogen is being transmitted to humans or other mammals.OspC is critical for survival in or transmission to the tick or mammalian host.<ref>PMID:11169111</ref> OspC is being produced by ''Borrelia burgdorferi'' during a very short time interval when infected ticks start feeding, but its synthesis is known to slow down greatly after transmission to a mammalian host. Interestingly, when an infested tick engorges, ''B. burgdorferi'' within the gut multiply and downregulate ospA. At the same time, the spirochetes start producing OspC in the feeding gut and continue to produce OspC throughout the transmission process and during the establishment of early vertebrate infection. This pattern of expression suggests that OspC may serve a function in the tick, possibly facilitating the migration of the spirochete from the vector gut to the salivary glands during transmission. After transmission from the tick, OspC may also play a role in colonization of host tissues.<ref>PMID:14722614</ref> It was demonstrated that those spirochetes that lack OspC are capable to replicate inside and migrate to the salivary glands of the tick vector but do not infect mammals. <ref name="Kum">D. Kumaran1, S. Eswaramoorthy1, B.J. Luft2, S. Koide3, J.J. Dunn1, C.L. Lawson1,4 and S. Swaminathan1. Crystal structure of outer surface protein C (OspC) from the Lyme disease spirochete, Borrelia burgdorferi.The EMBO Journal (2001) 20, 971 - 978 [http://dx.doi.org/DOI:10.1093/emboj/20.5.971]</ref> Without OspC the spirochetes are believed to be unable to adapt to the environment inside the host. Therefore, OspC is believed to determine [http://en.wikipedia.org/wiki/Virulence virulence] of the spirochete to mammals, including humans. | ||
=== Basic Structure Description === | === Basic Structure Description === | ||
OspC proteins are highly [http://en.wikipedia.org/wiki/Polymorphism_(biology) polymorphic] and this variability extends even to strains collected from a single geographical area. <ref name="Kum"/> <Structure load='1ggq' size='400' frame='true' align='right' caption=' ' scene='Insert optional scene name here' /> The outer surface protein C (ospC) locus ''Borrelia burgdorferi'' is at least an order of magnitude more variable than other genes in the species.<ref>PMID:15514047</ref> | OspC proteins are highly [http://en.wikipedia.org/wiki/Polymorphism_(biology) polymorphic] and this variability extends even to strains collected from a single geographical area. <ref name="Kum"/> <Structure load='1ggq' size='400' frame='true' align='right' caption=' ' scene='Insert optional scene name here' /> The outer surface protein C (ospC) locus ''Borrelia burgdorferi'' is at least an order of magnitude more variable than other genes in the species.<ref name="Brisson">PMID:15514047</ref> | ||
*Primary Structure | *Primary Structure | ||
The ospC gene is located on a 27 kb [http://en.wikipedia.org/wiki/Plasmid circular plasmid] and encodes a [http://en.wikipedia.org/wiki/Lipoprotein lipoprotein] of 22–23 kDa.<ref>PMID:7679385</ref> The protein is initially synthesized with an 18-amino-acid-long signal sequence which is removed during processing and [http://en.wiktionary.org/wiki/lipidated lipidation] at the amino proximal Cys residue. Each unit contains 162 amino acid residues. | The ospC gene is located on a 27 kb [http://en.wikipedia.org/wiki/Plasmid circular plasmid] and encodes a [http://en.wikipedia.org/wiki/Lipoprotein lipoprotein] of 22–23 kDa.<ref>PMID:7679385</ref> The protein is initially synthesized with an 18-amino-acid-long signal sequence which is removed during processing and [http://en.wiktionary.org/wiki/lipidated lipidation] at the amino proximal Cys residue. Each unit contains 162 amino acid residues. | ||
*Secondary Structure | *Secondary Structure | ||
OspC is predominantly <scene name='G18secL03Tpc4/Alpha_helix_highlighted/2'>α-helical</scene> in its secondary structure. <scene name='G18secL03Tpc4/Beta_sheets/2'>β-sheets</scene> are also present, but they are rather short and not promininent. The molecule also contains six <scene name='G18secL03Tpc4/Random_coils/1'>random coils</scene> throughout the structure on each subunit. OspC is unique when compared to its sister proteins, OspA and OspB, which are made up of beta-sheets mostly.<ref | OspC is predominantly <scene name='G18secL03Tpc4/Alpha_helix_highlighted/2'>α-helical</scene> in its secondary structure. <scene name='G18secL03Tpc4/Beta_sheets/2'>β-sheets</scene> are also present, but they are rather short and not promininent. The molecule also contains six <scene name='G18secL03Tpc4/Random_coils/1'>random coils</scene> throughout the structure on each subunit. OspC is unique when compared to its sister proteins, OspA and OspB, which are made up of beta-sheets mostly.<ref name="Brisson"/> | ||
*Tertiary Structure | *Tertiary Structure | ||
A single OspC monomer subunit is composed of 4 long and 1 short α-helices. Also, 2 short segments of β-sheets are observed near the binding site of the molecule. | A single OspC monomer subunit is composed of 4 long and 1 short α-helices. Also, 2 short segments of β-sheets are observed near the binding site of the molecule. | ||
