Isolation and characterization of the ribosomal L1 protein from olive

Abstract

Despite as a ribosomal protein, L1 is known as the inhibitor ofthe cellular aging gene and it has been reported to have roles inapoptosis. The ribosomal L1 protein is larger than the LSU ofribosome and contains 2 domains as 2-layered alpha/beta domainand 3-layered alpha/beta domain. In ribosomes, it functions intranslocation and orientation of tRNAs. Although the ribosomalL1 (RL1) gene has been studied in many plants, reports on oliveRL1 (OeRL1) are very rare. This study presents molecular char-acterization of RL1 gene from olive.OeRL1 was isolated from a cDNA library we constructedfrom unfruited olive leaves in July. Homology analyses were con-ducted using BLAST programs. Nucleotide and amino acid com-positions, molecular weight, isoelectric point (pI) and AT/GCratio were determined using BioEdit and ExPASy programs. Cel-lular location of the L1 protein was determined using SOSUI-GramN program. Signal peptide detection, transmembranedomain detection, three dimensional (3D) structure analysis, andphylogenetic analysis were conducted using SignalP 4.1,THHMM, I-TASSER/Cn3D and MEGA7, respectively.OeL1 was found to have an open reading frame of 909 basepairs coding 220 amino acids that constitutes a molecular weightof 24.9 kDA and a high pI of 9.87. Lysine, leucine and valinehad higher rates. The hydrophilic nature suggested by Kyte andDoolittle analysis despite high rates of leucine and valine suggestsan amphipathic nature of the protein that can bind to bothhydrophilic and hydrophobic proteins and / or function in bothmedia. A 1.59 AT/GC rate is significant comparing to that of itshomologs from other plants. Sitoplasmic location predicted bySOSUI-GranN is in agreement with the hypothesis suggesting anamphyphatic nature for OeRL1. Likewise, no signal peptide wasdetected and it was predicted to have at least one transmembranedomain. Further characterization of OeRL1 with respect toexpression pattern and biochemical function continues.