What is the relationship between a gene and a protein?

The terminology can be somewhat confusing. Dysferlin is a protein, and "the dysferlin gene" means "the gene which contains the instructions for producing the dysferlin protein." Each gene tells the cell how to put together the building blocks for one specific protein. However, the gene (DNA) sits inside a different compartment of the cell (the nucleus) from the location of the cellular machines that make proteins (ribosomes). Therefore, the gene must first make a copy of itself (called messenger RNA - mRNA), which is smaller and more portable than DNA and is able to leave the nucleus to reach the ribosomes. A ribosome then reads each set of three nucleotides in the mRNA code andĀ converts the instructions into a chain of amino acidsĀ that attach together to form a protein. The mRNA also tells the ribosome where to start the protein and when the protein is finished; namely, when it should stop attaching new amino acids to the protein. Because the nucleotides are read in groups of three, it is important for the ribosome to know how to group the nucleotides. If the nucleotides are grouped incorrectly, the ribosome will choose the wrong amino acids and the protein will not function. Usually, when a protein is not properly produced, it is because there is some mutation in the gene which contains its instructions.