| Primary Identifier | IPR036430 | Type | Homologous_superfamily |
| Short Name | RNase_T2-like_sf |
| description | Ribonuclease T2 (RNase T2) is a widespread family of secreted RNases found in every organism examined thus far. This family includes RNase Rh, RNase MC1, RNase LE, and self-incompatibility RNases (S-RNases) [, , , , ]. Plant T2 RNases are expressed during leaf senescence in order to scavenge phosphate from ribonucleotides. They are also expressed in response to wounding or pathogen invasion. S-RNases are thought to prevent self-fertilization by acting as selective cytotoxins of "self"pollen. Generally, RNases have two distinct binding sites: the primary site (B1 site) and the subsite (B2 site), for nucleotides located at the 5'- and 3'- terminal ends of the sissile bond, respectively.The fungal ribonucleases T2 from Aspergillus oryzae, M from Aspergillus saitoi and Rh from Rhizopus niveus are structurally and functionally related 30 Kd glycoproteins []that cleave the 3'-5' internucleotide linkage of RNA via a nucleotide 2',3'-cyclic phosphate intermediate (). Two histidines residues have been shown [, ]to be involved in the catalytic mechanism of RNase T2 and Rh. These residues and the region around them are highly conserved ina number of other RNAses that have been found to be evolutionary related to these fungal enzymes.The structure of ribonuclease T2 is composed of an alpha+beta fold. |
