Pathways & interactions
Ribosomal protein L9/RNase H1, N-terminal (IPR009027)
Short name: Ribosomal_L9/RNase_H1_N
- Ribosomal protein L9 (IPR000244)
- Ribonuclease H1, N-terminal (IPR011320)
- Ribonuclease H1, eukaryote (IPR017067)
- Ribosomal protein L9, N-terminal (IPR020070)
- Ribosomal protein L9, bacteria/chloroplast (IPR020594)
- Ribosomal protein L9, N-terminal domain superfamily (IPR036935)
- Ribonuclease H1, N-terminal domain superfamily (IPR037056)
The N-terminal domain of the ribosomal protein L9 is a regulatory RNA-binding module that binds to 23rRNA. L9 is composed of two domains and functions as a structural protein in the large subunit of the ribosome.
The N-terminal domain of eukaryotic RNase HI, which is lacking in retroviral and prokaryotic enzymes, shows a striking structural similarity to the L9 N-terminal domain, and may also function as a regulatory RNA-binding module. Eukaryotic RNases HI possess either one or two copies of the small N-terminal domain, in addition to the well-conserved catalytic RNase H domain. RNase HI belongs to the family of ribonuclease H enzymes that recognise RNA:DNA hybrids and degrade the RNA component.
The structures of both the L9 [PMID: 8306963] and the RNase HI [PMID: 10448044] N-terminal domains consist of a three-stranded antiparallel beta-sheet sandwiched between two short alpha-helices. The hydrophobic core of the domain is formed by the conserved residues that are involved in the packing of the alpha-helices onto the beta-sheet. The (beta)2/alpha/beta/alpha topology of the domain differs from the structures of known RNA binding domains such as the double-stranded RNA binding domain (dsRBD), the hnRNP K homology (KH) domain and the RNP motif.
- SSF55658 (SSF55658)