MICRO CHAPTER 8

Super-resolution microscopy

A powerful form of light microscopy that uses fluorescent molecules to resolve structures as small as 5-50 nm in living cells.

Fluorescent Tagging

Method using reporter genes that encode proteins easily detectable or assayed, often fused to genes of interest.

Green fluorescent protein (GFP)

A reporter protein routinely used in fluorescent tagging to resolve different genetic elements.

Photoactivated localization microscopy

Technique that maps movement of individual molecules by using photoactivated probes.

DnaA

A protein that binds to specific sequences within the oriC region of E. coli to initiate chromosome replication.

oriC

Origin of chromosome replication in E. coli where DnaA binding occurs.

DnaA–ATP

The activated form of DnaA that initiates DNA replication.

SeqA protein

Binds to hemimethylated oriC to inhibit DnaA, blocking replication initiation.

Par system

A mechanism used by many bacteria to equally distribute chromosomes and plasmids during cell division.

Fts proteins

A group of essential proteins involved in bacterial cell division.

FtsZ

A protein crucial for binary fission in bacteria, related to tubulin.

Divisome

The cell division apparatus consisting of various Fts proteins.

Cyclic Di-GMP

A regulatory molecule that signals transition from planktonic growth to biofilm growth.

Biofilm

A microbial community attached to a surface, encapsulated in a self-produced extracellular matrix.

Germination

The process by which endospores convert back to vegetative cells under favorable conditions.

Heterocyst

Specialized cells in cyanobacteria dedicated to nitrogen fixation.

Patterning

The arrangement and distribution of cells in filamentous cyanobacteria during heterocyst formation.

Sporulation

The process of forming endospores in response to adverse environmental conditions.

Endospore

A dormant, resistant cell formed by certain bacteria during unfavorable conditions.

Transpeptidation

The final step in peptidoglycan synthesis, forming cross-links between glycan chains.

Autolysins

Enzymes that cut peptidoglycan to allow incorporation of new precursors in bacterial cell walls.

Toxin-antitoxin (TA) modules

Systems in bacteria where a toxin inhibits growth while an antitoxin counteracts this effect.

Cortex lytic enzymes (CLE)

Enzymes that degrade the cortex during endospore germination.

Vibrio cholerae

A bacterium characterized by biofilm formation and the regulation of polysaccharide production.

Pseudomonas aeruginosa

An opportunistic pathogen known for its biofilm-forming ability and resistance to antibiotics.

Phenotypic heterogeneity

Variability in the traits of genetically identical cells, often seen in bacterial populations.

Bactoprenol

A lipid carrier molecule that plays a key role in the insertion of peptidoglycan precursors.

FtsI

A penicillin-binding protein involved in peptidoglycan synthesis, targeted by antibiotics.

Quorum sensing

A regulatory system that enables bacteria to sense and respond to cell population density.

NtcA

A global transcription regulator in cyanobacteria that activates genes for heterocyst formation.

Spo0A

A key regulator that, when phosphorylated, promotes sporulation in Bacillus species.

Cyclic AMP

A second messenger important in various signaling pathways in bacteria.

N-acetylmuramic acid

A component of the peptidoglycan layer in bacterial cell walls.

MreB

A shape-determining protein in bacteria that forms a simple cytoskeleton.

Daptomycin

An antibiotic that disrupts bacterial cell membrane integrity.

Vancomycin

An antibiotic that inhibits peptidoglycan synthesis by binding to precursor molecules.

β-lactamases

Enzymes that confer antibiotic resistance by breaking down β-lactam antibiotics.

Chronic tuberculosis

A recurring infection caused by Mycobacterium tuberculosis, often linked to persister cells.

Efflux pumps

Proteins in bacterial membranes that transport antibiotics out of the cell, contributing to resistance.

Swarmer cells

Free-swimming cells in Caulobacter that cannot divide or replicate DNA.

GcrA

A transcriptional regulator in Caulobacter that promotes chromosome replication and stalk growth.