Skip to content
Snippets Groups Projects

Update lamassu-fam.md

Merged Update lamassu-fam.md
abernhei-main-patch-33909 into main
Merged Aude BERNHEIM requested to merge abernhei-main-patch-33909 into main
Viewing commit 16d0e051
Prev Next
Show latest version
1 file
+ 7
− 7
Compare changes
  • Side-by-side
  • Inline
content/3.defense-systems/lamassu-fam.md
+ 7
− 7
@@ -24,17 +24,17 @@ RelevantAbstracts:
# Lamassu-Fam
## Description
The original types of Lamassu systems are Lamassu Type 1:ref{doi=10.1126/science.aar4120} and 2:ref{doi=10.1016/j.chom.2022.09.017}. They both necessarily comprise two genes *lmuA* and *lmuB*, to which a third gene (*lmuC*) is added in the case of Lamassu Type 2.
The original types of Lamassu systems are Lamassu Type 1 :ref{doi=10.1126/science.aar4120} and Type 2 :ref{doi=10.1016/j.chom.2022.09.017}. They both necessarily comprise two genes *lmuA* and *lmuB*, to which a third gene (*lmuC*) is added in the case of Lamassu Type 2.
Lamassu has been suggested to be a large family of defense systems, that can be classified into multiple subtypes:ref{doi=10.1016/j.chom.2022.09.017}.
Lamassu has been suggested to be a large family of defense systems, that can be classified into multiple subtypes :ref{doi=10.1016/j.chom.2022.09.017}.
These systems all encode the *lmuB* gene, and in most cases also comprise *lmuC.* In addition to these two core genes, Lamassu systems of various subtypes encode a third protein, hypothesized to be the Abi effector protein (3). This effector can be proteins encoding endonuclease domains, SIR2-domains, or even hydrolase domains:ref{doi=10.1016/j.chom.2022.09.017}. Systems of the extended Lamassu-family can be found in 10% of prokaryotic genomes:ref{doi=10.1016/j.chom.2022.09.017}.
These systems all encode the *lmuB* gene, and in most cases also comprise *lmuC*. In addition to these two core genes, Lamassu systems of various subtypes encode a third protein, hypothesized to be the Abi effector protein. This effector can be proteins encoding endonuclease domains, SIR2-domains, or even hydrolase domains :ref{doi=10.1016/j.chom.2022.09.017}. Systems of the extended Lamassu-family can be found in 10% of prokaryotic genomes :ref{doi=10.1016/j.chom.2022.09.017}.
Lamassu were also described as DdmABC in *Vibrio cholerae* :ref{doi=10.1038/s41586-022-04546-y}:ref{doi=10.1101/2022.11.18.517080}. They were found to be antiplasmids and thus to eliminate plasmids from seventh pandemic *Vibrio cholerae* :ref{doi=10.1038/s41586-022-04546-y}.
Lamassu were also described as DdmABC in *Vibrio cholerae* :ref{doi=10.1038/s41586-022-04546-y, 10.1101/2022.11.18.517080}. They were found to be antiplasmids and thus to eliminate plasmids from seventh pandemic *Vibrio cholerae* :ref{doi=10.1038/s41586-022-04546-y}.
## Molecular mechanism
Lamassu systems function through abortive infection (Abi), but the molecular mechanism remains to be described. It was shown that, in Vibrio cholerae palindromic DNA sequences that are predicted to form stem-loop hairpin trigger the system:ref{doi=10.1101/2022.11.18.517080}.
Lamassu systems function through abortive infection (Abi), but the molecular mechanism remains to be described. It was shown that, in Vibrio cholerae palindromic DNA sequences that are predicted to form stem-loop hairpin trigger the system :ref{doi=10.1101/2022.11.18.517080}.
## Example of genomic structure
@@ -44,11 +44,11 @@ Here is an example of a Lamassu-Fam_Cap4_nuclease found in the RefSeq database:
![lamassu-fam](/lamassu-fam/Lamassu-Fam_Cap4_nuclease.svg){max-width=750px}
Lamassu-Fam_Cap4_nuclease subsystem in the genome of *Pseudomonas sp.* (GCF_016925675.1) is composed of 3 proteins: LmuB_SMC_Hydrolase_protease (WP_205519025.1), LmuC_acc_Cap4_nuclease (WP_205478326.1)and, LmuA_effector_Cap4_nuclease_II (WP_205478325.1).
Lamassu-Fam_Cap4_nuclease subsystem in the genome of *Pseudomonas sp.* (GCF_016925675.1) is composed of 3 proteins: LmuB_SMC_Hydrolase_protease (WP_205519025.1), LmuC_acc_Cap4_nuclease (WP_205478326.1) and, LmuA_effector_Cap4_nuclease_II (WP_205478325.1).
![lamassu-fam](/lamassu-fam/Lamassu-Fam_Mrr.svg){max-width=750px}
Lamassu-Fam_Mrr subsystem in the genome of *Escherichia coli* (GCF_011404895.1) is composed of 2 proteins: LmuA_effector_Mrr (WP_044864610.1)and, LmuB_SMC_Cap4_nuclease_II (WP_226199836.1).
Lamassu-Fam_Mrr subsystem in the genome of *Escherichia coli* (GCF_011404895.1) is composed of 2 proteins: LmuA_effector_Mrr (WP_044864610.1) and, LmuB_SMC_Cap4_nuclease_II (WP_226199836.1).
![lamassu-fam](/lamassu-fam/Lamassu-Fam_Hydrolase.svg){max-width=750px}