MCB 7200: Molecular Biology

•Biotechnology terminology•Common hosts and experimental organisms•Transcription and translation•Prokaryotic gene organization & expression

Terminology

• Molecular biology-The study of biology on a molecular level including the structure, function, and makeup of biologically important molecules such as DNA, RNA, and proteins

• Recombinant DNA technology-a set of techniques for manipulating DNA, including: the identification and cloning of genes; the study of the expression of cloned genes; and the production of large quantities of gene product

• Genetic engineering-the process of transferring DNA from one organism into another that results in a genetic modification

• Biotechnology-production of goods and services using biological organisms, systems, and processes

• Molecular biotechnology-rDNA technology + biotechnology

Selected developments in the history of molecular biology/biotechnology

1944-Avery, MacLeod & McCarty determine DNA is the genetic material1953-Watson & Crick determine the structure of DNA1970-First restriction endonuclease isolated1973-Boyer & Cohen establish recombinant DNA technology1976-DNA sequencing techniques developed1980-U.S. Supreme Court rules genetically modified microorganisms can be patented1981-First DNA synthesizers sold1988-PCR method published1990-Human genome project initiated1996-Complete DNA sequence of a eukaryote (yeast) determined1997-Nuclear cloning of a mammal (a sheep named Dolly)2000-Arabidopsis genome sequenced2001-Human genome sequenced2002-Complete human gene microarrays (gene chips) available2006-Fire & Mellow discover RNAi (gene silencing by dsRNA)2009-FDA approves first drug produced in a genetically engineered animal (a goat)2012-Gurdon & Yamanaka find 4 regulatory genes convert adult cells into stem cells

Many scientific disciplines contribute to molecular biotechnology, which generates a

wide range of commercial products

Molecular Biology Model Systemshttps://www.dnalc.org/resources/animations/model_organisms.html

•Viruses•Bacteria (E. coli)•Yeast (Saccharomyces cerevisiae)•Round worms (Caenorhabditis elegans)•Fruit fly (Drosophila melanogaster)•Zebrafish (Danio rerio)•Arabidopsis thaliana (thale cress)•Mouse (Mus musculus)

Copyright © 2013 by W. H. Freeman and CompanyMolecular Cell Biology, 7th EditionLodish et al.

Figure 1.13 Each experimental organism used in cell biology has advantages for certain types of

studies.

Copyright © 2013 by W. H. Freeman and CompanyMolecular Cell Biology, 7th EditionLodish et al.

Figure 1.13 (Continued) Each experimental organism used in cell biology has advantages for

certain types of studies. Listen to the podcast!

Copyright © 2013 by W. H. Freeman and CompanyMolecular Cell Biology, 7th EditionLodish et al.

Review protein secretion and protein targeting

• Signal peptide sequences• Consider gram negative vs.

gram positive bacteria• Consider eukaryotic cells• In eukaryotic cells, short

peptide sequences (or other modifications) tell a protein where to go

• See MCB Chapter 13 & 14-Protein sorting animations

Central Dogma of Biology

DNA RNA Proteintranscription translation

reversetranscription

DNAreplication

$$$Molecular

Biotechnology

Chemical structure of DNA and RNA

Chemical structure of dsDNA

Chemical structure of dsDNA

Prokaryotic gene expression

In prokaryotes, RNA polymerase binds to the -10 and -35 regions of the promoter relative to

the start site of transcription (+1)

promoter operator