1MGR

Crystal structure of RNase Sa3,cytotoxic microbial ribonuclease

Summary for 1MGR

• Entry DOI: 10.2210/pdb1mgr/pdb
• Related: 1MGW 1RGG
• Descriptor: Guanyl-specific ribonuclease Sa3, SULFATE ION (3 entities in total)
• Functional Keywords: alpha/beta protein, ub rolls, hydrolase
• Biological source: Streptomyces aureofaciens
• Cellular location: Secreted: P30289
• Total number of polymer chains: 1
• Total formula weight: 11153.19

Authors

Sevcik, J.,Urbanikova, L.,Leland, P.A.,Raines, R.T. (deposition date: 2002-08-16, release date: 2003-02-04, Last modification date: 2024-10-30)

Primary citation

Sevcik, J.,Urbanikova, L.,Leland, P.A.,Raines, R.T.
Links X-ray Structure of Two Crystalline Forms of a Streptomycete Ribonuclease with Cytotoxic Activity
J.Biol.Chem., 277:47325-47330, 2002

PubMed Abstract: Ribonuclease (RNase) Sa3 is secreted by the Gram-positive bacterium Streptomyces aureofaciens. The enzyme catalyzes the cleavage of RNA on the 3' side of guanosine residues. Here, x-ray diffraction analysis was used to determine the three-dimensional structure of two distinct crystalline forms of RNase Sa3 to a resolution of 2.0 and 1.7 A. These two structures are similar to each other as well as to that of a homolog, RNase Sa. All of the key active-site residues of RNase Sa (Asn(42), Glu(44), Glu(57), Arg(72), and His(88)) are located in the putative active site of RNase Sa3. Also herein, RNase Sa3 is shown to be toxic to human erythroleukemia cells in culture. Like onconase, which is an amphibian ribonuclease in Phase III clinical trials as a cancer chemotherapeutic, RNase Sa3 is not inhibited by the cytosolic ribonuclease inhibitor protein. Thus, a prokaryotic ribonuclease can be toxic to mammalian cells.

PubMed: 12228255
DOI: 10.1074/jbc.M208425200

Experimental method

X-RAY DIFFRACTION (1.7 Å)