Journal: BMC Struct Biol / Year: 2008 Title: Crystal structure of human IPS-1/MAVS/VISA/Cardif caspase activation recruitment domain. Authors: Jane A Potter / Richard E Randall / Garry L Taylor / Abstract: BACKGROUND: IPS-1/MAVS/VISA/Cardif is an adaptor protein that plays a crucial role in the induction of interferons in response to viral infection. In the initial stage of the intracellular antiviral ...BACKGROUND: IPS-1/MAVS/VISA/Cardif is an adaptor protein that plays a crucial role in the induction of interferons in response to viral infection. In the initial stage of the intracellular antiviral response two RNA helicases, retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-association gene 5 (MDA5), are independently able to bind viral RNA in the cytoplasm. The 62 kDa protein IPS-1/MAVS/VISA/Cardif contains an N-terminal caspase activation and recruitment (CARD) domain that associates with the CARD regions of RIG-I and MDA5, ultimately leading to the induction of type I interferons. As a first step towards understanding the molecular basis of this important adaptor protein we have undertaken structural studies of the IPS-1 MAVS/VISA/Cardif CARD region. RESULTS: The crystal structure of human IPS-1/MAVS/VISA/Cardif CARD has been determined to 2.1A resolution. The protein was expressed and crystallized as a maltose-binding protein (MBP) fusion ...RESULTS: The crystal structure of human IPS-1/MAVS/VISA/Cardif CARD has been determined to 2.1A resolution. The protein was expressed and crystallized as a maltose-binding protein (MBP) fusion protein. The MBP and IPS-1 components each form a distinct domain within the structure. IPS-1/MAVS/VISA/Cardif CARD adopts a characteristic six-helix bundle with a Greek-key topology and, in common with a number of other known CARD structures, contains two major polar surfaces on opposite sides of the molecule. One face has a surface-exposed, disordered tryptophan residue that may explain the poor solubility of untagged expression constructs. CONCLUSION: The IPS-1/MAVS/VISA/Cardif CARD domain adopts the classic CARD fold with an asymmetric surface charge distribution that is typical of CARD domains involved in homotypic protein-protein ...CONCLUSION: The IPS-1/MAVS/VISA/Cardif CARD domain adopts the classic CARD fold with an asymmetric surface charge distribution that is typical of CARD domains involved in homotypic protein-protein interactions. The location of the two polar areas on IPS-1/MAVS/VISA/Cardif CARD suggest possible types of associations that this domain makes with the two CARD domains of MDA5 or RIG-I. The N-terminal CARD domains of RIG-I and MDA5 share greatest sequence similarity with IPS-1/MAVS/VISA/Cardif CARD and this has allowed modelling of their structures. These models show a very different charge profile for the equivalent surfaces compared to IPS-1/MAVS/VISA/Cardif CARD.
SHEET THE SHEET STRUCTURE OF THIS MOLECULE IS BIFURCATED. IN ORDER TO REPRESENT THIS FEATURE IN ... SHEET THE SHEET STRUCTURE OF THIS MOLECULE IS BIFURCATED. IN ORDER TO REPRESENT THIS FEATURE IN THE SHEET RECORDS BELOW, TWO SHEETS ARE DEFINED.
Mass: 53411.324 Da / Num. of mol.: 1 Fragment: MMBP RESIDUES 27-392, CARD DOMAIN RESIDUES 3-93,MMBP RESIDUES 27-392, CARD DOMAIN RESIDUES 3-93 Source method: isolated from a genetically manipulated source Details: THE CONSTRUCT IS A FUSION OF E. COLI MBP (RESIDUES 2-366) AND HUMAN IPS-1 CARD (RESIDUES 1 TO 93) Source: (gene. exp.) Escherichia coli (E. coli), (gene. exp.) Homo sapiens (human) Gene: malE, PU06_05845, MAVS, IPS1, KIAA1271, VISA / Production host: ESCHERICHIA COLI (E. coli) References: UniProt: A0A0B1N7A9, UniProt: Q7Z434, UniProt: P0AEX9*PLUS