Protein or the physical region of the protein that participates in chemical catalysis. In solution proteins also undergo variation in structure through thermal vibration and the collision with other molecules. Proteins can be informally divided into three main classes, which correlate with typical tertiary structures: globular proteins, fibrous proteins, and membrane proteins. Almost all globular proteins are soluble and many are enzymes. Fibrous proteins are often structural, such as collagen, the major component of connective tissue, or keratin, the protein component of hair and nails. Membrane proteins often serve as receptors or provide channels for polar or charged molecules to pass
Ribosomal protein leader form an intrinsic transcription termination stem-loop. When cellular concentrations of the ribosomal protein are not high, they are occupied in the ribosome, and are not available in significant quantities to bind the mRNA leader. This leads to increased expression of the gene, which leads to the synthesis of more copies of the ribosomal protein. Many examples of ribosomal protein leaders are known in bacteria, including ribosomal protein L20 leader and ribosomal S15 leader. Ribosomal protein leader A ribosomal protein leader is a mechanism used in cells to control the cellular concentration of a protein that forms a part of the