THE GENETICS AND USEFULNESS OF PLASMIDS
Paul A. Gulig
I. Plasmids - General
A. Extrachromosomal DNA, usually circular
B. Usually encode ancillary functions for in vitro growth
C. Can be essential for specific environments: virulence, antibiotics resistanc
Bacterial Genetics and Physiology
Plasmid biology and genetics
What is expected of you for the unit on plasmids.
1. What is a plasmid?
2. How do plasmids replicate? (understand the 2 basic models of [RNA vs. protein
3. What is host range and
GMS 6038 Bacterial Genetics and Physiology
You should be able to answer these questions by the end of the first week of class,
based on your previous education and/or looking over the PDF/PowerPoint linked to the
course web page:
1. Which three antibiotics are useful because you can usually isolate spontaneous
resistant mutants for them relatively easily? What are their targets?
nalidixic acid - gyrase - gyrA
streptomycin - ribosome - rpsL
rifampin - RNA polymerase - rpoB
Bacterial Genetics Quiz 2 - 2011
1. A. A donor strain and recipient strain are mixed together in a broth. Genetic markers are transferred
from the donor to the recipient. What forms of genetic exchange could be involved?
all three - conjugation, tr
Quorum Sensing in Biofilms: Why Bacteria Behave the Way They D.
1 of 23
Human pathogens form biofilms on food and food contact surfaces, thereby enhancing their ability to survive harsh
Regulation of gene expression
I. General information
A. orderly and controlled expression
growth phase, nutritional and stress conditions, environment vs. in host
B. most regulation at initiation of transcription; however, some post-transcriptional mRNA s
phage M13 gIII gene encodes pIII protein 5 copy
protein on surface.
Cloning a coding sequence in frame with the glll
gene allows the expression of the encoded
protein on the
Protein localization (Chapters 2 and 14).
I. cytoplasm not a problem
II. cell (inner) membrane
III. exported beyond cell (inner) membrane
IV. secreted outside of cell (note different use than previous years)
V. translocase systems for cell membrane (Sec a
Study guide for Bacteriophage
I. Concepts to understand
A. basic phage structure - spectrum of size and complexity
B. life cycle - virulent vs. temperate phage (lytic vs. lysogenic cycles)
C. early vs. late gene expression (what types of genes generally f
NOTE: I expect you to understand the principles of antimicrobial therapy and the
general characteristics of the major antibiotics listed below.
A. Based on selective toxicity - toxic to bacteria, not bad for us
1. What would the immediate and the far reaching effect be of deleting the N gene of phage Lambda
when it infects E. coli?
genes beyond the left and right terminators would not be expressed
lytic phase cannot proceed
Notes on Bacterial DNA Replication
Here is what I think you should be familiar with from your reading of Chapter 1 of
the text. I am assuming that you will be re-familiarized with the basic biochemistry of
DNA replication. Well concentrate of things that
Translation - Antibiotics
mRNA with ribosome
binding site upstream of
Initiation Factors (IFs)
Recognition of tRNA
Gene expression in bacteria (Chapter 2)
Note: I am assuming that you remember the central dogma of molecular biology (DNA
to RNA to protein), the basics of expression that is common to bacteria and eukaryotes
(e.g., mRNA, rRNA, tRNA, rtc.), genetic code,
A Couple of Examples of
I. Catabolite repression - CAP regulon
A. misnomer, since the CAP protein is an activator
B. catabolite-sensitive operons
C. cAMP made by adenylate cyclase (cya gene) - ATP cAMP
- decrease energy level - increased
BACTERIAL GENETICS AND PHYSIOLOGY
PAUL A. GULIG, PH.D.
OFFICE R1-250 392-0050 LAB R1-144 392-0682
Office hours - By Appointment
The goal of this course is to enable students with some microbiology and molecular genetics
WORKING WITH BACTERIAL GROWTH YIELDS AND
OK, so the simple formula for calculating YIELDS is:
Nt=N0 x 2g
Nt is the number of cells at time t
N0 is the starting number of cells
g is the number of generations that occurred
t is the elaps
"The fundamental differences in the structure and physiology of bacteria as infectious
agents vs. us as hosts are the bases for most of the damaging effects of infectious
disease and our ability to fight infectious disease with antibiotics."
Study Guide for Biofilms and Quorum Sensing
We covered this stuff quickly and briefly, so the expectations are similar.
Biofilms - communities of bacteria usually at surface-liquid interfaces. Usually are mixtures of
different bacteria. Free (individual)