| Stirrup | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of an archaeal intein-encoded homing endonuclease pi-pfui | |||||||||
| Identifiers | |||||||||
| Symbol | Stirrup | ||||||||
| Pfam | PF09061 | ||||||||
| InterPro | IPR015146 | ||||||||
| SCOP2 | 1dq3 / SCOPe / SUPFAM | ||||||||
| |||||||||
In molecular biology, the Stirrup is a protein domain found only in the domain archaea, in prokaryotic protein ribonucleotide reductases. It obtains its name due to its resemblance to an old fashioned Japanese stirrup. Stirrip has a molecular mass of 9 kDa and is folded into an alpha/beta structure. It allows for binding of the reductase to DNA via electrostatic interactions, since it has a predominance of positive charges distributed on its surface. [1]