InterPro domain: IPR044774

This entry represents the DEXQ-box helicase domain found in Suv3 and related proteins. Suv3 is an NTP-dependent RNA/DNA helicase that is necessary for the degradation of mature mtRNAs. It localizes predominantly in the mitochondria, where it forms an RNA-degrading complex called mitochondrial degradosome (mtEXO) with exonuclease PNP (polynucleotide phosphorylase), that degrades 3' overhang double-stranded RNA with a 3'-to-5' directionality in an ATP-dependent manner. Suv3 plays a role in the RNA surveillance system in mitochondria; it regulates the stability of mature mRNAs, the removal of aberrantly formed mRNAs and the rapid degradation of non coding processing intermediates [ 1 ]. It also confers salinity and drought stress tolerance by maintaining both photosynthesis and antioxidant machinery, probably via an increase in plant hormone levels such as gibberellic acid (GA3), the cytokinin zeatin (Z), and indole-3-acetic acid (IAA) [ 2 , 3 ].

Proteins containing this domain also include some bacterial RNA helicases.

1. Human Suv3 protein reveals unique features among SF2 helicases. Acta Crystallogr. D Biol. Crystallogr. 67, 988-96
2. OsSUV3 transgenic rice maintains higher endogenous levels of plant hormones that mitigates adverse effects of salinity and sustains crop productivity. Rice (N Y) 7, 17
3. OsSUV3 dual helicase functions in salinity stress tolerance by maintaining photosynthesis and antioxidant machinery in rice (Oryza sativa L. cv. IR64). Plant J 76, 115-27