Structural highlights
Function
[KRR1_YEAST] Required for 40S ribosome biogenesis. Involved in nucleolar processing of pre-18S ribosomal RNA and ribosome assembly. Essential for vegetative growth.[1] [2] [3] [4] [FAF1_YEAST] Required for pre-rRNA processing and 40S ribosomal subunit assembly. Seems to act in the processing of 35S rRNA at the A(0), A(1), and A(2) cleavage sites.
Publication Abstract from PubMed
Ribosome formation in Saccharomyces cerevisiae requires a large number of transiently associated assembly factors that coordinate processing and folding of pre-rRNA and binding of ribosomal proteins. Krr1 and Faf1 are two interacting proteins present in early 90 S precursor particles of the small ribosomal subunit. Here, we determined a co-crystal structure of the core domain of Krr1 bound to a 19-residue fragment of Faf1 at 2.8 A resolution. The structure reveals that Krr1 consists of two packed K homology (KH) domains, KH1 and KH2, and resembles archaeal Dim2-like proteins. We show that KH1 is a divergent KH domain that lacks the RNA-binding GXXG motif and is involved in binding another assembly factor, Kri1. KH2 contains a canonical RNA-binding surface and additionally associates with an alpha-helix of Faf1. Specific disruption of the Krr1-Faf1 interaction impaired early 18 S rRNA processing at sites A0, A1, and A2 and caused cell lethality, but it did not prevent incorporation of the two proteins into pre-ribosomes. The Krr1-Faf1 interaction likely maintains a critical conformation of 90 S pre-ribosomes required for pre-rRNA processing. Our results illustrate the versatility of KH domains in protein interaction and provide insight into the role of Krr1-Faf1 interaction in ribosome biogenesis.
Interaction between ribosome assembly factors Krr1 and Faf1 is essential for formation of small ribosomal subunit in yeast.,Zheng S, Lan P, Liu X, Ye K J Biol Chem. 2014 Aug 15;289(33):22692-703. doi: 10.1074/jbc.M114.584490. Epub, 2014 Jul 2. PMID:24990943[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gromadka R, Rytka J. The KRR1 gene encodes a protein required for 18S rRNA synthesis and 40S ribosomal subunit assembly in Saccharomyces cerevisiae. Acta Biochim Pol. 2000;47(4):993-1005. PMID:11996121
- ↑ Sasaki T, Toh-E A, Kikuchi Y. Yeast Krr1p physically and functionally interacts with a novel essential Kri1p, and both proteins are required for 40S ribosome biogenesis in the nucleolus. Mol Cell Biol. 2000 Nov;20(21):7971-9. PMID:11027267
- ↑ Gromadka R, Karkusiewicz I, Rempola B, Rytka J. Functional and physical interactions of Krr1p, a Saccharomyces cerevisiae nucleolar protein. Acta Biochim Pol. 2004;51(1):173-87. PMID:15094838 doi:http://dx.doi.org/045101173
- ↑ Bernstein KA, Gallagher JE, Mitchell BM, Granneman S, Baserga SJ. The small-subunit processome is a ribosome assembly intermediate. Eukaryot Cell. 2004 Dec;3(6):1619-26. PMID:15590835 doi:http://dx.doi.org/10.1128/EC.3.6.1619-1626.2004
- ↑ Zheng S, Lan P, Liu X, Ye K. Interaction between ribosome assembly factors Krr1 and Faf1 is essential for formation of small ribosomal subunit in yeast. J Biol Chem. 2014 Aug 15;289(33):22692-703. doi: 10.1074/jbc.M114.584490. Epub, 2014 Jul 2. PMID:24990943 doi:http://dx.doi.org/10.1074/jbc.M114.584490
