|1b1j, resolution 2.00Å ()|
CRYSTAL STRUCTURE OF HUMAN ANGIOGENIN VARIANT H13A.
Human angiogenin (Ang), an unusual member of the pancreatic RNase superfamily, is a potent inducer of angiogenesis in vivo. Its ribonucleolytic activity is weak (10(4) to 10(6)-fold lower than that of bovine RNase A), but nonetheless seems to be essential for biological function. Ang has been implicated in the establishment of a wide range of human tumours and has therefore emerged as an important target for the design of new anti-cancer compounds. We report high-resolution crystal structures for native Ang in two different forms (Pyr1 at 1.8 A and Met-1 at 2.0 A resolution) and for two active-site variants, K40Q and H13A, at 2.0 A resolution. The native structures, together with earlier mutational and biochemical data, provide a basis for understanding the unique functional properties of this molecule. The major structural features that underlie the weakness of angiogenin's RNase activity include: (i) the obstruction of the pyrimidine-binding site by Gln117; (ii) the existence of a hydrogen bond between Thr44 and Thr80 that further suppresses the effectiveness of the pyrimidine site; (iii) the absence of a counterpart for the His119-Asp121 hydrogen bond that potentiates catalysis in RNase A (the corresponding aspartate in Ang, Asp116, has been recruited to stabilise the blockage of the pyrimidine site); and (iv) the absence of any precise structural counterparts for two important purine-binding residues of RNase A. Analysis of the native structures has revealed details of the cell-binding region and nuclear localisation signal of Ang that are critical for angiogenicity. The cell-binding site differs dramatically from the corresponding regions of RNase A and two other homologues, eosinophil-derived neurotoxin and onconase, all of which lack angiogenic activity. Determination of the structures of the catalytically inactive variants K40Q and H13A has now allowed a rigorous assessment of the relationship between the ribonucleolytic and biological activities of Ang. No significant change outside the enzymatic active site was observed in K40Q, establishing that the loss of angiogenic activity for this derivative is directly attributable to disruption of the catalytic apparatus. The H13A structure shows some changes beyond the ribonucleolytic site, but sites involved in cell-binding and nuclear translocation are essentially unaffected by the amino acid replacement.
Refined crystal structures of native human angiogenin and two active site variants: implications for the unique functional properties of an enzyme involved in neovascularisation during tumour growth., Leonidas DD, Shapiro R, Allen SC, Subbarao GV, Veluraja K, Acharya KR, J Mol Biol. 1999 Jan 22;285(3):1209-33. PMID:9918722
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[ANGI_HUMAN] Defects in ANG are the cause of susceptibility to amyotrophic lateral sclerosis type 9 (ALS9) [MIM:611895]. ALS is a degenerative disorder of motor neurons in the cortex, brain stem and spinal cord. ALS is characterized by muscular weakness and atrophy.
[ANGI_HUMAN] May function as a tRNA-specific ribonuclease that abolishes protein synthesis by specifically hydrolyzing cellular tRNAs. Binds to actin on the surface of endothelial cells; once bound, angiogenin is endocytosed and translocated to the nucleus. Angiogenin induces vascularization of normal and malignant tissues. Angiogenic activity is regulated by interaction with RNH1 in vivo.
About this Structure
- Leonidas DD, Shapiro R, Allen SC, Subbarao GV, Veluraja K, Acharya KR. Refined crystal structures of native human angiogenin and two active site variants: implications for the unique functional properties of an enzyme involved in neovascularisation during tumour growth. J Mol Biol. 1999 Jan 22;285(3):1209-33. PMID:9918722 doi:10.1006/jmbi.1998.2378
- ↑ Wu D, Yu W, Kishikawa H, Folkerth RD, Iafrate AJ, Shen Y, Xin W, Sims K, Hu GF. Angiogenin loss-of-function mutations in amyotrophic lateral sclerosis. Ann Neurol. 2007 Dec;62(6):609-17. PMID:17886298 doi:10.1002/ana.21221
- ↑ Greenway MJ, Alexander MD, Ennis S, Traynor BJ, Corr B, Frost E, Green A, Hardiman O. A novel candidate region for ALS on chromosome 14q11.2. Neurology. 2004 Nov 23;63(10):1936-8. PMID:15557516
- ↑ Greenway MJ, Andersen PM, Russ C, Ennis S, Cashman S, Donaghy C, Patterson V, Swingler R, Kieran D, Prehn J, Morrison KE, Green A, Acharya KR, Brown RH Jr, Hardiman O. ANG mutations segregate with familial and 'sporadic' amyotrophic lateral sclerosis. Nat Genet. 2006 Apr;38(4):411-3. Epub 2006 Feb 26. PMID:16501576 doi:10.1038/ng1742
- ↑ Crabtree B, Thiyagarajan N, Prior SH, Wilson P, Iyer S, Ferns T, Shapiro R, Brew K, Subramanian V, Acharya KR. Characterization of human angiogenin variants implicated in amyotrophic lateral sclerosis. Biochemistry. 2007 Oct 23;46(42):11810-8. Epub 2007 Sep 27. PMID:17900154 doi:10.1021/bi701333h
- ↑ Gellera C, Colombrita C, Ticozzi N, Castellotti B, Bragato C, Ratti A, Taroni F, Silani V. Identification of new ANG gene mutations in a large cohort of Italian patients with amyotrophic lateral sclerosis. Neurogenetics. 2008 Feb;9(1):33-40. Epub 2007 Dec 18. PMID:18087731 doi:10.1007/s10048-007-0111-3
- ↑ Conforti FL, Sprovieri T, Mazzei R, Ungaro C, La Bella V, Tessitore A, Patitucci A, Magariello A, Gabriele AL, Tedeschi G, Simone IL, Majorana G, Valentino P, Condino F, Bono F, Monsurro MR, Muglia M, Quattrone A. A novel Angiogenin gene mutation in a sporadic patient with amyotrophic lateral sclerosis from southern Italy. Neuromuscul Disord. 2008 Jan;18(1):68-70. Epub 2007 Aug 20. PMID:17703939 doi:S0960-8966(07)00676-1
- ↑ Saxena SK, Rybak SM, Davey RT Jr, Youle RJ, Ackerman EJ. Angiogenin is a cytotoxic, tRNA-specific ribonuclease in the RNase A superfamily. J Biol Chem. 1992 Oct 25;267(30):21982-6. PMID:1400510
- ↑ Dickson KA, Kang DK, Kwon YS, Kim JC, Leland PA, Kim BM, Chang SI, Raines RT. Ribonuclease inhibitor regulates neovascularization by human angiogenin. Biochemistry. 2009 May 12;48(18):3804-6. doi: 10.1021/bi9005094. PMID:19354288 doi:10.1021/bi9005094