Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 213.6 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 247.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 247.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Deprecated: Implicit conversion from float 247.2 to int loses precision in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 534
Warning: imagejpeg(C:\Inetpub\vhosts\kidney.de\httpdocs\phplern\28510217
.jpg): Failed to open stream: No such file or directory in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 117 Biophys+Rev
2016 ; 8
(Suppl 1
): 123-133
Nephropedia Template TP
gab.com Text
Twit Text FOAVip
Twit Text #
English Wikipedia
Protein-induced DNA linking number change by sequence-specific DNA binding
proteins and its biological effects
#MMPMID28510217
Leng F
Biophys Rev
2016[Nov]; 8
(Suppl 1
): 123-133
PMID28510217
show ga
Sequence-specific DNA-binding proteins play essential roles in many fundamental
biological events such as DNA replication, recombination, and transcription. One
common feature of sequence-specific DNA-binding proteins is to introduce
structural changes to their DNA recognition sites including DNA-bending and DNA
linking number change (?Lk). In this article, I review recent progress in
studying protein-induced ?Lk by several sequence-specific DNA-binding proteins,
such as E. coli cAMP receptor protein (CRP) and lactose repressor (LacI). It was
demonstrated recently that protein-induced ?Lk is an intrinsic property for
sequence-specific DNA-binding proteins and does not correlate to protein-induced
other structural changes, such as DNA bending. For instance, although CRP bends
its DNA recognition site by 90°, it was not able to introduce a ?Lk to it.
However, LacI was able to simultaneously bend and introduce a ?Lk to its DNA
binding sites. Intriguingly, LacI also constrained superhelicity within LacI-lac
O1 complexes if (-) supercoiled DNA templates were provided. I also discuss how
protein-induced ?Lk help sequence-specific DNA-binding proteins regulate their
biological functions. For example, it was shown recently that LacI utilizes the
constrained superhelicity (?Lk) in LacI-lac O1 complexes and serves as a
topological barrier to constrain free, unconstrained (-) supercoils within the
401-bp DNA loop. These constrained (-) supercoils enhance LacI's binding affinity
and therefore the repression of the lac promoter. Other biological functions
include how DNA replication initiators ? O and DnaA use the induced ?Lk to
open/melt bacterial DNA replication origins.