上泽充通大￥ Shanghai Jiao Tong University 1896 1920 1987 2006 m Lecture 11-1 Genetic Engineering Chapter 11 in BROCK BIOLOGY OF MICROORGANISMS NG UNI Chen Feng School of Life Science and Technology, Shanghai Jiao Tong University http://micro.sjtu.edu.cn
1896 1920 1987 2006 Lecture 11-1 Genetic Engineering Chapter 11 in BROCK BIOLOGY OF MICROORGANISMS Chen Feng School of Life Science and Technology, Shanghai Jiao Tong University http://micro.sjtu.edu.cn
I.Methods for Manipulating DNA 11.1 Restriction and Modification Enzymes Genetic engineering:using in vitro techniques to alter genetic material in the laboratory Basic techniques include Restriction enzymes ·Gel electrophoresis Nucleic acid hybridization ·Nucleic acid probes ·Molecular cloning ·Cloning vectors Chen Feng,Lecture of Microbiology
Chen Feng, Lecture of Microbiology I. Methods for Manipulating DNA 11.1 Restriction and Modification Enzymes Genetic engineering: using in vitro techniques to alter genetic material in the laboratory • Basic techniques include • Restriction enzymes • Gel electrophoresis • Nucleic acid hybridization • Nucleic acid probes • Molecular cloning • Cloning vectors
Restriction Enzymes Restriction enzymes:recognize specific DNA sequences and cut DNA at those sites Widespread among prokaryotes ·Rare in eukaryotes Protect prokaryotes from hostile foreign DNA (e.g.,viral genomes) e Essential for in vitro DNA manipulation Chen Feng,Lecture of Microbiology
Chen Feng, Lecture of Microbiology Restriction Enzymes Restriction enzymes: recognize specific DNA sequences and cut DNA at those sites • Widespread among prokaryotes • Rare in eukaryotes • Protect prokaryotes from hostile foreign DNA (e.g., viral genomes) • Essential for in vitro DNA manipulation
Restriction Enzymes Three classes of restriction enzymes Type ll cleave DNA within their recognition sequence and are most useful for specific DNA manipulation(Figure 11.1a) Restriction enzymes recognize inverted repeat sequences(palindromes) Typically 4-8 base pairs long;EcoRl recognizes a 6-base- pair sequence Sticky ends or blunt ends Chen Feng,Lecture of Microbiology
Chen Feng, Lecture of Microbiology Three classes of restriction enzymes • Type II cleave DNA within their recognition sequence and are most useful for specific DNA manipulation (Figure 11.1a) Restriction enzymes recognize inverted repeat sequences (palindromes) • Typically 4–8 base pairs long; EcoRI recognizes a 6-basepair sequence Sticky ends or blunt ends Restriction Enzymes
Figure 11.1a 5' G-A-A-T-T-C 3' 3' C-T-T-A-A-G 5' A-A-T-T- 5' -G 3' 3' -C-T-T-A-A. G- 5' Single-stranded (a) “sticky”ends 2012 Pearson Education,Inc
Figure 11.1a Single-stranded “sticky” ends © 2012 Pearson Education, Inc