Related Experiment Video
Updated: Jun 3, 2026
14:25
Method for Efficient Refolding and Purification of Chemoreceptor Ligand Binding Domain
Published on: December 12, 2017
Structural analysis of a novel class of R-M controller proteins: C.Csp231I from Citrobacter sp. RFL231
J E McGeehan1, S D Streeter, S-J Thresh
1Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK. john.mcgeehan@port.ac.uk
Journal of Molecular Biology
|March 29, 2011
Summary
This study reveals a novel class of bacterial controller proteins, C.Csp231I, with unique structural features. These proteins utilize unusual DNA binding sites and C-terminal helices, impacting gene regulation and horizontal gene transfer.
Area of Science:
- Molecular Biology
- Structural Biology
- Bacteriology
Background:
- Controller proteins regulate gene expression in bacterial restriction-modification (R-M) systems.
- These proteins are crucial for horizontal gene transfer and form cooperative genetic switches.
Purpose of the Study:
- To present a detailed analysis of a novel class of controller proteins, using C.Csp231I as an example.
- To elucidate the unique structural and DNA-binding characteristics of these proteins.
Main Methods:
- Biophysical analysis
- Biochemical assays
- High-resolution structural determination
Main Results:
- Identified a novel class of controller proteins (C.Csp231I) with unique C-terminal helices.
- Discovered an unusual DNA binding site characterized by AAAA tracts, suggesting significant DNA bending.
- Observed a positively charged surface potentially involved in complete DNA wrapping around the protein dimer.
Conclusions:
- The novel structural elements of C.Csp231I contribute to its function in DNA binding and regulation.
- These findings offer new insights into the mechanisms of bacterial gene control and horizontal gene transfer.
Related Concept Videos
01:29Cytoskeletal Proteins in Bacteria
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
01:32Microtubule Associated Motor Proteins
Eukaryotic cells have different motor proteins for transporting various cargo within the cell. These motor proteins differ based on the filament they associate with, the direction they move within the cell, and the type of cargo they transport. Motor proteins that associate with microtubules are known as microtubule-associated motor proteins. There are two families of microtubule-associated motor proteins —Kinesins and Dyneins. Both these proteins assist in the transport of cellular cargos...
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
01:23Types of RNA
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
01:14Rab Proteins
Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...