6i3f
From Proteopedia
Crystal structure of the complex of human angiotensinogen and renin at 2.55 Angstrom
Structural highlights
DiseaseRENI_HUMAN Defects in REN are a cause of renal tubular dysgenesis (RTD) [MIM:267430. RTD is an autosomal recessive severe disorder of renal tubular development characterized by persistent fetal anuria and perinatal death, probably due to pulmonary hypoplasia from early-onset oligohydramnios (the Potter phenotype).[1] Defects in REN are the cause of familial juvenile hyperuricemic nephropathy type 2 (HNFJ2) [MIM:613092. It is a renal disease characterized by juvenile onset of hyperuricemia, slowly progressive renal failure and anemia.[2] FunctionRENI_HUMAN Renin is a highly specific endopeptidase, whose only known function is to generate angiotensin I from angiotensinogen in the plasma, initiating a cascade of reactions that produce an elevation of blood pressure and increased sodium retention by the kidney. Publication Abstract from PubMedThe renin-angiotensin cascade is a hormone system that regulates blood pressure and fluid balance. Renin-mediated cleavage of the angiotensin I peptide from the N-terminus of angiotensinogen (AGT) is the rate-limiting step of this cascade; however, the detailed molecular mechanism underlying this step is unclear. Here, we solved the crystal structures of glycosylated human AGT (2.30 A resolution), its encounter complex with renin (2.55 A), AGT cleaved in its reactive center loop (RCL; 2.97 A) and spent AGT from which the N-terminal angiotensin peptide was removed (2.63 A). These structures revealed that AGT undergoes profound conformational changes and binds renin through a tail-into-mouth allosteric mechanism that inserts the N-terminus into a pocket equivalent to a hormone binding site on other serpins. These changes fully extended the N-terminal tail, with the scissile bond for angiotensin release docked in renin's active site. Insertion of the N-terminus into this pocket accompanied a complete unwinding of helix H of AGT, which, in turn, formed key interactions with renin in the complementary binding interface. Mutagenesis and kinetic analyses confirmed that renin-mediated production of angiotensin I is controlled by interactions of amino acid residues and glycan components outside renin's active site cleft. Our findings indicate that AGT adapts unique serpin features for hormone delivery and binds renin through concerted movements in the N-terminal tail and in its main body to modulate angiotensin release. These insights provide a structural basis for the development of agents that attenuate angiotensin release by targeting AGT's hormone binding pocket. Structural basis for the specificity of renin-mediated angiotensinogen cleavage.,Yan Y, Zhou A, Carrell RW, Read RJ J Biol Chem. 2018 Dec 18. pii: RA118.006608. doi: 10.1074/jbc.RA118.006608. PMID:30563843[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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