Open AccessCrystal structures of an ICAM‐5 ectodomain fragment show electrostatic‐based homophilic adhesions
Author(s) -
Recacha Rosario,
Jiménez David,
Tian Li,
Barredo Román,
Gahmberg Carl G.,
Casasnovas José M.
Publication year - 2014
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s1399004714009468
Subject(s) - molecule , ectodomain , chemistry , adhesion , cell adhesion molecule , icam 1 , crystal (programming language) , stereochemistry , crystallography , biology , microbiology and biotechnology , receptor , biochemistry , organic chemistry , computer science , programming language
Intercellular cell adhesion molecule‐5 (ICAM‐5) is a member of the ICAM subfamily that is exclusively expressed in the telencephalon region of the brain. The crystal structure of the four most N‐terminal glycosylated domains (D1–D4) of ICAM‐5 was determined in three different space groups and the D1–D5 fragment was modelled. The structures showed a curved molecule with two pronounced interdomain bends between D2 and D3 and between D3 and D4, as well as some interdomain flexibility. In contrast to ICAM‐1, ICAM‐5 has patches of positive and negative electrostatic charge at D1–D2 and at D3–D5, respectively. ICAM‐5 can mediate homotypic interactions. In the crystals, several charge‐based intermolecular interactions between the N‐terminal and C‐terminal moieties of the ICAM‐5 molecules were observed, which defined an interacting surface in the D1–D4 fragment. One of the crystal lattices has a molecular assembly that could represent the homophilic ICAM‐5 cell adhesion complex in neurons.