Re: [ccp4bb] Asn/Gln - pi-stacking prevalence

2018-11-13 Thread Daniel Anderson
While working on PDB entries 1F0N and 1F0P, I aligned the side-chain 
dipoles of 4 asparagines with the side-chain dipoles of tryptophans 
(ring nitrogen is slightly negative, the rest of the 5-membered ring is 
slightly positive). Aligning dipoles simultaneously optimized hydrogen 
bonding for the 4 asparagines. So that could be a simultaneous pi-stack 
and dipole interaction (and hydrogen bonds).


me, et al J. Molecular Biology (2001) 307, 671-681.




On 11/10/18 1:45 AM, Michael Jarva wrote:


Dear ccp4 community,


I have recently been working with a structure that has an Asparagine 
that makes a planar stacking connection with a Tryptophan ring 
(pep_ASN-TRP_v2.png), that seem to be a true pi-stacking interaction 
and I'd like to find more examples of this.



I've found a few other examples in the literature but they are 
mostly amide hydrogen-pi interactions (4PTI_ASN-TYR_v2.png and 
1N4W_ASN-FAD_v2.png), which can be seen by the way the Asn is dipping 
down into the pi-cloud. One potential exception is of a DNA-binding 
protein where the orientation is more planar (3HXQ_GLN-DNA_v2.png).



So, I'm looking for examples of Asparagine or Glutamine pi-stacking 
and am sure there are more of them out there and would greatly 
appreciate any examples.



best regards

Michael


Michael Jarva, PhD
ACRF Chemical Biology Division

The Walter and Eliza Hall Institute of Medical Research
1G Royal Parade
Parkville Victoria 3052
Australia

Phone: +61 3 9345 2493 
Email: jarv...@wehi.edu.au | Web: http://www.wehi.edu.au/

The ACRF Chemical Biology Division is supported by the

Australian Cancer Research Foundation


___

The information in this email is confidential and intended solely for 
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The Walter and Eliza Hall Institute acknowledges the Wurundjeri people 
of the Kulin
Nation as the traditional owners of the land where our campuses are 
located and

the continuing connection to country and community.
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Re: [ccp4bb] Asn/Gln - pi-stacking prevalence

2018-11-12 Thread Michael Jarva

Thank you to Tomas, Bill, and Andrew for their tips and insights! It was really 
all I hoped for and more.


The eLife paper with its downloadable text file of mined pi-pi stacking is 
really useful and is easily adapted into fast visual inspection with pymol. 
Problem now is having more examples to look at than I have time for!



cheers

michael



From: Tomas Malinauskas 
Sent: Sunday, November 11, 2018 3:11 AM
To: Michael Jarva
Cc: CCP4BB@jiscmail.ac.uk
Subject: Re: [ccp4bb] Asn/Gln - pi-stacking prevalence

Dear Michael,

On Sat, Nov 10, 2018 at 9:56 AM Michael Jarva  wrote:
>
> Dear ccp4 community,
>
>
> I have recently been working with a structure that has an Asparagine that 
> makes a planar stacking connection with a Tryptophan ring 
> (pep_ASN-TRP_v2.png), that seem to be a true pi-stacking interaction and I'd 
> like to find more examples of this.

You could check the following paper:
https://elifesciences.org/articles/31486
Pi-Pi contacts are an overlooked protein feature relevant to phase separation

They have a list of examples (including Asn-Trp pi-pi stacking) in PDB
(Figure 1, data source):
Pi-Pi contact annotations for the full PDB set.
Text file listing the pi-pi contacts observed across our non-redundant
PDB set, with contact types shown by residue annotations where single
amino acid names refer to sidechains and pairs of amino acids refer to
the backbone peptide bond between residue i and residue i + 1.
https://doi.org/10.7554/eLife.31486.005

Best wishes,
Tomas

Dr. Tomas Malinauskas
University of Oxford
Wellcome Centre for Human Genetics
Division of Structural Biology
Roosevelt Drive
Oxford OX3 7BN
United Kingdom
to...@strubi.ox.ac.uk
tomas.malinaus...@gmail.com





From: William G. Scott 
Sent: Sunday, November 11, 2018 1:54 AM
To: Michael Jarva
Cc: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] Asn/Gln - pi-stacking prevalence

Hi Michael:

It always makes me happy to see that there are people who care about this.

3.3 to 3.4 Å should be an ideal distance for this, and, as you note, the lone 
pair
residing on the (sp^3-hybridized) nitrogen would have to be oriented for
favorable overlap, which is a bit harder to deduce from your figure.

The other rotomer would place oxygen at that position. Because it is 
double-bonded
to the gamma carbon, the lone pairs are oriented differently, and the pi-bond 
would
be approximately parallel to the plane containing the tryptophan, which would 
give
a nice pi-stacking interaction similar to what is seen with adjacent base pairs 
in nucleic acids.

Expectation bias, as well as having partial charges turned on during 
refinement, might
influence the rotomeric state of examples from the PDB, so be careful of social 
consensus.
With classical electostatics, N has a partial positive charge, and O has a 
partial negative
charge.  (If you think about it, all pi-stacking interactions, from the point 
of view of classical
electrostatics, would be somewhat repulsive.)

Good luck with this, and let us know of the outcome.


Bill



William G. Scott
Director, Program in Biochemistry and Molecular Biology
Professor, Department of Chemistry and Biochemistry
and The Center for the Molecular Biology of RNA
University of California at Santa Cruz
Santa Cruz, California 95064
USA

http://scottlab.ucsc.edu<http://scottlab.ucsc.edu/>

> On Nov 10, 2018, at 1:45 AM, Michael Jarva  wrote:
>
> Dear ccp4 community,
>
> I have recently been working with a structure that has an Asparagine that 
> makes a planar stacking connection with a Tryptophan ring 
> (pep_ASN-TRP_v2.png), that seem to be a true pi-stacking interaction and I'd 
> like to find more examples of this.
>
> I've found a few other examples in the literature but they are mostly amide 
> hydrogen-pi interactions (4PTI_ASN-TYR_v2.png and 1N4W_ASN-FAD_v2.png), which 
> can be seen by the way the Asn is dipping down into the pi-cloud. One 
> potential exception is of a DNA-binding protein where the orientation is more 
> planar (3HXQ_GLN-DNA_v2.png).
>
> So, I'm looking for examples of Asparagine or Glutamine pi-stacking and am 
> sure there are more of them out there and would greatly appreciate any 
> examples.
>
> best regards
> Michael
>
> Michael Jarva, PhD
> ACRF Chemical Biology Division
> The Walter and Eliza Hall Institute of Medical Research
> 1G Royal Parade
> Parkville Victoria 3052
> Australia
> Phone: +61 3 9345 2493
> Email: jarv...@wehi.edu.au | Web: http://www.wehi.edu.au/
> The ACRF Chemical Biology Division is supported by the
> Australian Cancer Research Foundation
>
> ___
>
> The information in this email is confidential and intended solely for the 
> addressee.
> You must not disclose, forward, print or use it without the permission

Re: [ccp4bb] Asn/Gln - pi-stacking prevalence

2018-11-10 Thread Tomas Malinauskas
Dear Michael,

On Sat, Nov 10, 2018 at 9:56 AM Michael Jarva  wrote:
>
> Dear ccp4 community,
>
>
> I have recently been working with a structure that has an Asparagine that 
> makes a planar stacking connection with a Tryptophan ring 
> (pep_ASN-TRP_v2.png), that seem to be a true pi-stacking interaction and I'd 
> like to find more examples of this.

You could check the following paper:
https://elifesciences.org/articles/31486
Pi-Pi contacts are an overlooked protein feature relevant to phase separation

They have a list of examples (including Asn-Trp pi-pi stacking) in PDB
(Figure 1, data source):
Pi-Pi contact annotations for the full PDB set.
Text file listing the pi-pi contacts observed across our non-redundant
PDB set, with contact types shown by residue annotations where single
amino acid names refer to sidechains and pairs of amino acids refer to
the backbone peptide bond between residue i and residue i + 1.
https://doi.org/10.7554/eLife.31486.005

Best wishes,
Tomas

Dr. Tomas Malinauskas
University of Oxford
Wellcome Centre for Human Genetics
Division of Structural Biology
Roosevelt Drive
Oxford OX3 7BN
United Kingdom
to...@strubi.ox.ac.uk
tomas.malinaus...@gmail.com



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Re: [ccp4bb] Asn/Gln - pi-stacking prevalence

2018-11-10 Thread William G. Scott
Hi Michael:

It always makes me happy to see that there are people who care about this.

3.3 to 3.4 Å should be an ideal distance for this, and, as you note, the lone 
pair
residing on the (sp^3-hybridized) nitrogen would have to be oriented for 
favorable overlap, which is a bit harder to deduce from your figure.

The other rotomer would place oxygen at that position. Because it is 
double-bonded
to the gamma carbon, the lone pairs are oriented differently, and the pi-bond 
would
be approximately parallel to the plane containing the tryptophan, which would 
give
a nice pi-stacking interaction similar to what is seen with adjacent base pairs 
in nucleic acids.

Expectation bias, as well as having partial charges turned on during 
refinement, might
influence the rotomeric state of examples from the PDB, so be careful of social 
consensus.
With classical electostatics, N has a partial positive charge, and O has a 
partial negative 
charge.  (If you think about it, all pi-stacking interactions, from the point 
of view of classical
electrostatics, would be somewhat repulsive.)

Good luck with this, and let us know of the outcome.


Bill



William G. Scott
Director, Program in Biochemistry and Molecular Biology
Professor, Department of Chemistry and Biochemistry
and The Center for the Molecular Biology of RNA
University of California at Santa Cruz
Santa Cruz, California 95064
USA

http://scottlab.ucsc.edu

> On Nov 10, 2018, at 1:45 AM, Michael Jarva  wrote:
> 
> Dear ccp4 community,
> 
> I have recently been working with a structure that has an Asparagine that 
> makes a planar stacking connection with a Tryptophan ring 
> (pep_ASN-TRP_v2.png), that seem to be a true pi-stacking interaction and I'd 
> like to find more examples of this.
> 
> I've found a few other examples in the literature but they are mostly amide 
> hydrogen-pi interactions (4PTI_ASN-TYR_v2.png and 1N4W_ASN-FAD_v2.png), which 
> can be seen by the way the Asn is dipping down into the pi-cloud. One 
> potential exception is of a DNA-binding protein where the orientation is more 
> planar (3HXQ_GLN-DNA_v2.png).
> 
> So, I'm looking for examples of Asparagine or Glutamine pi-stacking and am 
> sure there are more of them out there and would greatly appreciate any 
> examples.
> 
> best regards
> Michael
> 
> Michael Jarva, PhD
> ACRF Chemical Biology Division
> The Walter and Eliza Hall Institute of Medical Research
> 1G Royal Parade
> Parkville Victoria 3052
> Australia
> Phone: +61 3 9345 2493 
> Email: jarv...@wehi.edu.au | Web: http://www.wehi.edu.au/
> The ACRF Chemical Biology Division is supported by the
> Australian Cancer Research Foundation
> 
> ___ 
> 
> The information in this email is confidential and intended solely for the 
> addressee.
> You must not disclose, forward, print or use it without the permission of the 
> sender.
> 
> The Walter and Eliza Hall Institute acknowledges the Wurundjeri people of the 
> Kulin 
> Nation as the traditional owners of the land where our campuses are located 
> and 
> the continuing connection to country and community.
> ___
> 
> To unsubscribe from the CCP4BB list, click the following link:
> https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB=1
> <4PTI_ASN-TYR_v2.png><3HXQ_GLN-DNA_v2.png><1N4W_ASN-FAD_v2.png>



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