MS07-P01 Purification and crystallization of novel archaean protein of the LSM family Maryia Fando (Group of Structural Studies of Ribosomal proteins, Institute of Protein Research, Pushchino, Russia) Natalia Lekontseva (Group of Structural Studies of Ribosomal proteins, Institute of Protein Research, Pushchino, Russia) Alexey Nikulin (Laboratory of Structural Studies of the Translation Apparatus, Institute of Protein Research, Pushchino, Russia)email:
Lsm (Sm-like) proteins are found in representatives of all the three domains of life. They provide biogenesis and functioning of RNA molecules in the cells. Bacterial Lsm proteins called Hfq exhibit RNA-chaperone activity promoting interaction between regulatory sRNA and mRNA during regulation of translation [1], [2]. Eukaryotic Sm proteins are core proteins of the spliceosome while eukaryotic Lsm proteins are involved in the mRNA degradation [3]. Functions of the archaeal Lsm proteins (SmAP) in the cell have been studied pitiable, although there is some data on their participation in the processing of some.
Our work concerns with structural and functional studies of an archaeal Lsm protein from Halobacterium salinarum. This protein has remarkable differences of the sequences compared with the homologues and, in fact, represents a minimal Lsm core. My current task is to determine the structure of the protein and its complexes with ribonucleotides and short RNA to define specificity and structural aspects of the Lsm-RNA interaction. We have obtained a genetic construct carrying the gene of the SmAP from H. salinarum (HsaSmAP). The protein was isolated and purified in preparative scale; it has been crystallized and a high-resolution diffraction dataset has been collected at ERSF in Grenoble.
The work is supported by RFBR grant #18-04-00222.

[1] Sun, X. et al. (2002). Nucleic Acids Res. 30, 3662–3671.

[2] Valentin-Hansen, P. et al. (2004). Mol. Microbiol. 51. 1525–1533.

[3] Thore, S. et al. (2003) J. Biol. Chem. 278, 1239–1247.

Keywords: Archaeal Lsm proteins , RNA binding, X-ray diffraction analysis