bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Окт. 29, 2023
Abstract
DNA
loop
extrusion
by
SMC
proteins
is
a
key
process
underlying
chromosomal
organization.
It
unknown
how
extruders
interact
with
telomeres
where
chromosome
ends
are
covered
dense
array
of
tens
neighboring
DNA-binding
proteins.
Using
complementary
in
vivo
and
vitro
single-molecule
approaches,
we
study
the
interaction
between
loop-extruding
condensin
arrays
Rap1,
double-stranded-DNA-binding
telomeric
protein
Saccharomyces
cerevisiae
.
We
show
that
linear
Rap1
can
completely
halt
extrusion,
blocking
efficiency
depends
on
length
gap
size
In
cells,
found
to
act
as
contact
insulators
accumulate
at
their
borders,
direct
implications
for
resolution
dicentric
chromosomes
produced
telomere
fusions.
Our
findings
DNA-bound
efficiently
proteins,
which
may
impact
wide
range
cellular
processes
from
functions
transcription
repair.
Cell Reports,
Год журнала:
2023,
Номер
42(7), С. 112672 - 112672
Опубликована: Июнь 21, 2023
Prokaryotic
adaptation
is
strongly
influenced
by
the
horizontal
acquisition
of
beneficial
traits
via
mobile
genetic
elements
(MGEs),
such
as
viruses/bacteriophages
and
plasmids.
However,
MGEs
can
also
impose
a
fitness
cost
due
to
their
often
parasitic
nature
differing
evolutionary
trajectories.
In
response,
prokaryotes
have
evolved
diverse
immune
mechanisms
against
MGEs.
Recently,
our
understanding
abundance
diversity
prokaryotic
systems
has
greatly
expanded.
These
defense
degrade
invading
material,
inhibit
genome
replication,
or
trigger
abortive
infection,
leading
population
protection.
this
review,
we
highlight
these
strategies,
focusing
on
most
recent
discoveries.
The
study
defenses
not
only
sheds
light
microbial
evolution
but
uncovers
novel
enzymatic
activities
with
promising
biotechnological
applications.
Current Opinion in Microbiology,
Год журнала:
2023,
Номер
73, С. 102282 - 102282
Опубликована: Фев. 28, 2023
Horizontal
gene
transfer
is
central
to
bacterial
adaptation
and
facilitated
by
mobile
genetic
elements
(MGEs).
Increasingly,
MGEs
are
being
studied
as
agents
with
their
own
interests
adaptations,
the
interactions
have
one
another
recognised
having
a
powerful
effect
on
flow
of
traits
between
microbes.
Collaborations
conflicts
nuanced
can
both
promote
inhibit
acquisition
new
material,
shaping
maintenance
newly
acquired
genes
dissemination
important
adaptive
through
microbiomes.
We
review
recent
studies
that
shed
light
this
dynamic
oftentimes
interlaced
interplay,
highlighting
importance
genome
defence
systems
in
mediating
MGE-MGE
conflicts,
outlining
consequences
for
evolutionary
change,
resonate
from
molecular
microbiome
ecosystem
levels.
Molecular Cell,
Год журнала:
2024,
Номер
84(5), С. 883 - 896.e7
Опубликована: Фев. 2, 2024
DNA
loop-extruding
SMC
complexes
play
crucial
roles
in
chromosome
folding
and
immunity.
Prokaryotic
Wadjet
(JET)
limit
the
spread
of
plasmids
through
cleavage,
yet
mechanisms
for
plasmid
recognition
are
unresolved.
We
show
that
artificial
circularization
renders
linear
susceptible
to
JET
nuclease
cleavage.
Unlike
free
DNA,
cleaves
immobilized
at
a
specific
site,
plasmid-anchoring
point,
showing
anchor
hinders
extrusion
but
not
Structures
plasmid-bound
JetABC
reveal
two
presumably
stalled
motor
units
drastically
rearranged
from
resting
state,
together
entrapping
U-shaped
segment,
which
is
further
converted
kinked
V-shaped
cleavage
substrate
by
JetD
binding.
Our
findings
uncover
mechanical
bending
residual
unextruded
as
molecular
signature
non-self
elimination.
moreover
elucidate
key
elements
loop
extrusion,
including
direction
structure
DNA-holding
state.
Current Opinion in Microbiology,
Год журнала:
2024,
Номер
78, С. 102436 - 102436
Опубликована: Фев. 17, 2024
Bacteria
have
evolved
a
variety
of
defence
mechanisms
to
protect
against
mobile
genetic
elements,
including
restriction-modification
systems
and
CRISPR–Cas.
In
recent
years,
dozens
previously
unknown
(DSs)
been
discovered.
Notably,
diverse
DSs
often
coexist
within
the
same
genome,
some
co-occur
at
frequencies
significantly
higher
than
would
be
expected
by
chance,
implying
potential
synergistic
interactions.
Recent
studies
provided
evidence
that
enhance
or
complement
one
another.
Here,
we
review
interactions
between
mechanistic,
regulatory,
ecological
evolutionary
levels.
Nucleic Acids Research,
Год журнала:
2023,
Номер
51(7), С. 3288 - 3306
Опубликована: Март 7, 2023
Abstract
Cells
are
continuously
facing
the
risk
of
taking
up
foreign
DNA
that
can
compromise
genomic
integrity.
Therefore,
bacteria
in
a
constant
arms
race
with
mobile
genetic
elements
such
as
phages,
transposons
and
plasmids.
They
have
developed
several
active
strategies
against
invading
molecules
be
seen
bacterial
‘innate
immune
system’.
Here,
we
investigated
molecular
arrangement
Corynebacterium
glutamicum
MksBEFG
complex,
which
is
homologous
to
MukBEF
condensin
system.
We
show
here
MksG
nuclease
degrades
plasmid
DNA.
The
crystal
structure
revealed
dimeric
assembly
through
its
C-terminal
domain
TOPRIM
topoisomerase
II
family
enzymes
contains
corresponding
ion
binding
site
essential
for
cleavage
topoisomerases.
MksBEF
subunits
exhibit
an
ATPase
cycle
vitro
reason
this
reaction
cycle,
combination
activity
provided
by
MksG,
allows
processive
degradation
Super-resolution
localization
microscopy
Mks
system
spatially
regulated
via
polar
scaffold
protein
DivIVA.
Introduction
plasmids
results
increase
bound
indicating
activation
vivo.
