2rqa
From Proteopedia
Solution structure of LGP2 CTD
Structural highlights
Function[DHX58_HUMAN] Acts as a regulator of DDX58/RIG-I and IFIH1/MDA5 mediated antiviral signaling. Cannot initiate antiviral signaling as it lacks the CARD domain required for activating MAVS/IPS1-dependent signaling events. Can have both negative and positive regulatory functions related to DDX58/RIG-I and IFIH1/MDA5 signaling and this role in regulating signaling may be complex and could probably depend on characteristics of the infecting virus or target cells, or both. Its inhibitory action on DDX58/RIG-I signaling may involve the following mechanisms: competition with DDX58/RIG-I for binding to the viral RNA, binding to DDX58/RIG-I and inhibiting its dimerization and interaction with MAVS/IPS1, competing with IKBKE in its binding to MAVS/IPS1 thereby inhibiting activation of interferon regulatory factor 3 (IRF3). Its positive regulatory role may involve unwinding or stripping nucleoproteins of viral RNA thereby facilitating their recognition by DDX58/RIG-I and IFIH1/MDA5. Involved in the innate immune response to various RNA viruses and some DNA viruses such as poxviruses, and also to the bacterial pathogen Listeria monocytogenes. Can bind both ssRNA and dsRNA, with a higher affinity for dsRNA. Shows a preference to 5'-triphosphorylated RNA, although it can recognize RNA lacking a 5'-triphosphate.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe RIG-I like receptor (RLR) comprises three homologues: RIG-I (retinoic acid-inducible gene I), MDA5 (melanoma differentiation-associated gene 5), and LGP2 (laboratory of genetics and physiology 2). Each RLR senses different viral infections by recognizing replicating viral RNA in the cytoplasm. The RLR contains a conserved C-terminal domain (CTD), which is responsible for the binding specificity to the viral RNAs, including double-stranded RNA (dsRNA) and 5'-triphosphated single-stranded RNA (5'ppp-ssRNA). Here, the solution structures of the MDA5 and LGP2 CTD domains were solved by NMR and compared with those of RIG-I CTD. The CTD domains each have a similar fold and a similar basic surface but there is the distinct structural feature of a RNA binding loop; The LGP2 and RIG-I CTD domains have a large basic surface, one bank of which is formed by the RNA binding loop. MDA5 also has a large basic surface that is extensively flat due to open conformation of the RNA binding loop. The NMR chemical shift perturbation study showed that dsRNA and 5'ppp-ssRNA are bound to the basic surface of LGP2 CTD, whereas dsRNA is bound to the basic surface of MDA5 CTD but much more weakly, indicating that the conformation of the RNA binding loop is responsible for the sensitivity to dsRNA and 5'ppp-ssRNA. Mutation study of the basic surface and the RNA binding loop supports the conclusion from the structure studies. Thus, the CTD is responsible for the binding affinity to the viral RNAs. Solution structures of cytosolic RNA sensor MDA5 and LGP2 C-terminal domains: identification of the RNA recognition loop in RIG-I-like receptors.,Takahasi K, Kumeta H, Tsuduki N, Narita R, Shigemoto T, Hirai R, Yoneyama M, Horiuchi M, Ogura K, Fujita T, Inagaki F J Biol Chem. 2009 Jun 26;284(26):17465-74. Epub 2009 Apr 20. PMID:19380577[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||
Categories: Human | Large Structures | Fujita, T | Fuyuhiko, I | Hirai, R | Horiuchi, M | Kumeta, H | Narita, R | Ogura, K | Shigemoto, T | Takahasi, K | Tsuduki, N | Yoneyama, M | Atp-binding | Coiled coil | Cytoplasm | Helicase | Hydrolase | Immune response | Innate immunity | Nucleotide-binding | Polymorphism | Rna binding protein | Rna-binding
