The Biotechnology of Recombinant DNA rDNA

Most of the components that conuihute to cellular homeostasis are proteins—so much so that more than half of the dry weight of a cell is protein. Histones, cellular enzymes, membrane transport systems, and immunoglobulins are just a few examples of the proteins that carry out the biological functions of a living human cell. Proteins are hydrated three-dimensional structures, but at their most basic level, they are composed of linear sequences of amino acids that fold to create the spatial characteristics of the protein. These linear 

If the amino acid. sequence of a protein (and. hence, the codon sequence) is known, automated synthesis of DNA through chemical or enz.ymalic means represents a third way lhal genes can be engineered. This method is u.seful only for 

TABLE 6-1 Characteristics of Genomic Versus cONA Libraries  

Smirce of genetic muicrial Genomic DNA Cell or iis ie mRNA 

The recognition sites for restriction endonucleases arc specific palindromic sequences of DNA not more than 8 bp long. A number of these palindromes are listed in Table 6-2. A palindrome is a. sequence of letters that reads the same way forward and backward, for instance A man. a plan, a canal Panama . DNA-land, Did Hannah sec bees Hannah did. Restriction endonucleases cleave DNA at palindromic sites to yield several types of cuts  

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