Hello
I am attaching a Heme group onto a protein using CNS v1.1. My problem is
that I cannot get CNS to recognize the mass of the iron (Fe) correctly.
Using the prosthetics topology file from the HICup database, the MASS of the
iron is defined as follows in this topology file: (abbreviated for this
message)
MASS FE_1 55.84700
{etc...}
RESIdue HEM
GROUp
ATOM FE1 TYPE FE_1 CHARge 0.0 END
ATOM CHA TYPE C_2 CHARge 0.0 END
{etc...etc...}
END {HEM}
This topology file was then inserted into the "prosthetics" section in
generate.inp, with the patch definition inputed into the "special" section
at the end of the generate.inp under prosthetic groups.
My problem is: no matter what I input as the FE_1 mass, (1, 55.84, 155.84,
255.84 etc...) the 3sigma Fo-Fc map surrounding the "FE1" atom remains very
intense and remains unchanged. Although I have already placed an iron atom
at this position, the positive peak in the map doesn't go away. Later I
even placed a ! in front of the "MASS FE_1 55.84700" entry, and
generate.inp still proceeds smoothly without prompting any ERR messages.
(except for a few %READC_WRITE errors)
Any input on this question would be greatly appreciated. Thank you
Jimson
ATOM FE TYPE FE_1 CHARge 0.0 END
ATOM CHA TYPE C_2 CHARge 0.0
ATOM CHA
ATOM CHA
RESIdue HEM
{ Note: electrostatics should normally not be used in }
{ crystallographic refinement since it can produce }
{ artefacts. For this reason, all charges are set to }
{ zero by default. Edit them if necessary }
GROUp
ATOM FE TYPE FE_1 CHARge 0.0 END ! Nr of Hs = 0
