This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1qg3
From Proteopedia
CRYSTAL STRUCTURE OF A TANDEM PAIR OF FIBRONECTIN TYPE III DOMAINS FROM THE CYTOPLASMIC TAIL OF INTEGRIN ALPHA6 BETA4
Structural highlights
Disease[ITB4_HUMAN] Defects in ITGB4 are a cause of epidermolysis bullosa letalis with pyloric atresia (EB-PA) [MIM:226730]; also known as junctional epidermolysis bullosa with pyloric atresia (PA-JEB) or aplasia cutis congenita with gastrointestinal atresia. EB-PA is an autosomal recessive, frequently lethal, epidermolysis bullosa with variable involvement of skin, nails, mucosa, and with variable effects on the digestive system. It is characterized by mucocutaneous fragility, aplasia cutis congenita, and gastrointestinal atresia, which most commonly affects the pylorus. Pyloric atresia is a primary manifestation rather than a scarring process secondary to epidermolysis bullosa.[1] [2] [3] [4] [5] [6] [7] Defects in ITGB4 are a cause of generalized atrophic benign epidermolysis bullosa (GABEB) [MIM:226650]. GABEB is a non-lethal, adult form of junctional epidermolysis bullosa characterized by life-long blistering of the skin, associated with hair and tooth abnormalities.[8] Function[ITB4_HUMAN] Integrin alpha-6/beta-4 is a receptor for laminin. Plays a critical structural role in the hemidesmosome of epithelial cells. Is required for the regulation of keratinocyte polarity and motility.[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 integrin alpha6beta4 is an essential component of hemidesmosomes but it also plays a dynamic role in invasive carcinoma cells. The cytoplasmic tail of the beta4 subunit is uniquely large among integrins and includes two pairs of fibronectin type III domains separated by a connecting segment. Here we describe the crystal structure of the first tandem domain pair, a module that is critical for alpha6beta4 function. The structure reveals a novel interdomain interface and candidate protein-binding sites, including a large acidic cleft formed from the surfaces of both domains and a prominent loop that is reminiscent of the RGD integrin-binding loop of fibronectin. This is the first crystal structure of either a hemidesmosome component or an integrin cytoplasmic domain, and it will enable the intracellular functions of alpha6beta4 to be dissected at the atomic level. Crystal structure of a tandem pair of fibronectin type III domains from the cytoplasmic tail of integrin alpha6beta4.,de Pereda JM, Wiche G, Liddington RC EMBO J. 1999 Aug 2;18(15):4087-95. PMID:10428948[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||
