Crystal structure of a mutant of archaeal ribosomal protein L1 from Methanococcus jannaschii
- PDF / 763,131 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 99 Downloads / 179 Views
CTURE OF MACROMOLECULAR COMPOUNDS
Crystal Structure of a Mutant of Archaeal Ribosomal Protein L1 from Methanococcus jannaschii A. V. Sarskikh, A. G. Gabdulkhakov, O. S. Kostareva, A. A. Shklyaeva, and S. V. Tishchenko Institute of Protein Research, Russian Academy of Sciences, Institutskaya ul. 4, Pushchino, Moscow oblast, 142290 Russia email: [email protected] Received July 18, 2013
Abstract—The crystal structure of a mutant of archaeal ribosomal protein L1 from Methanococcus jannaschii with the deletion of a nonconserved positively charged cluster consisting of eight Cterminal amino acid re sidues is determined by the molecular replacement method at 1.75 Å resolution. This mutant is shown to form more stable and ordered crystals belonging to a space group other than that of the wildtype protein crystals. The positively charged Cterminal region has only a slight effect on the interaction between protein L1 and RNA molecules. Hence, this mutant can be used to prepare protein–RNA complexes and obtain their crys tals. DOI: 10.1134/S1063774514030158
INTRODUCTION Ribosomal protein L1 independently and specifi cally binds to 23S rRNA and is located on a side pro tuberance of the ribosome [1]. In addition, protein L1 can act as the regulatory protein in bacteria and archaea by binding to its own mRNA [2, 3]. Thus, this protein regulates its own synthesis and the synthesis of protein L11 in E. coli and the synthesis of proteins L1, L10, and L12 in archaea. The crystal structures of protein L1 in the free state and in complexes with specific fragments of 23S rRNA or mRNA from the bacteria Thermus thermophilus (TthL1) [4–7] and Aquifex aeolicus (AaeL1) [8] and the archaea Methanococcus thermolithotrophicus (MthL1) [9], Sulfolobus acidocaldarius (SacL1), and Methanococcus jannaschii (MjaL1) [10, 11] have been determined earlier. The highresolution structures of homologous complexes from the same organism are required for the reliable analysis of protein–RNA interactions. Only one such structure (from the bacte rium T. thermophilus) is currently known [7]. As a part
of studies aimed at determining the structures of homologous protein–RNA complexes of archaeal ribosomal proteins, efforts are made to optimize the conditions for protein crystallization. Protein MjaL1 rapidly binds to RNA and forms a more stable complex compared to protein L1 from other organisms (Table 1). The Cterminus of MjaL1 bears a nonconserved cluster containing six lysine re sidues. This region is not seen in the structure of MjaL1 either in the free state [11] or in a complex with mRNA [5]. The mutant of protein L1 (MjaL18C) lacking eight Cterminal aminoacid residues (KKEKAKKK) was produced and crystallized. Crys tals of MjaL18C are characterized by high stability and order. In the present work, we describe the struc ture of MjaL18C and perform a comparative analysis. It was shown that the nonconserved positively charged region of protein MjaL1 makes an insignificant contri bution to the interaction with RNA, and this form can b
Data Loading...
