HEME(1D) — Silicon Graphics

NAME

heme − depthcued display of the Cytochrome P450 protein molecule

SYNOPSIS

/usr/people/demos/heme

DESCRIPTION

Dr. Tom Poulos and Prof. Joseph Kraut of the University of California at San Diego have constructed a computer model of the Cytochrome P450 molecule to aid in their research into the structure of this enzyme. Computer graphics help in comparing electron density maps to the proposed protein structure by moving the hypothetical structure into regions of high electron density. Proximity of atoms provides information regarding chemical interaction.

Heme displays the Cytochrome protein with control of viewing transformations via pop-up menu selections. Also, display of various parts of the protein molecule can be toggled on and off.

Pop up the menu by holding down the CENTER mouse button. Menu selections are are toggled by placing the cursor atop the menu selection and pressing the LEFT mouse button. The menu disappears when the CENTER mouse button is released. Left Function
Menu 5Amino acids that interact with the heme group.
4 Backbone of P450, connecting alpha-carbons of amino acid subunits.
3Electron density contour around the iron atom.
2 Van der Waal surface of the heme group.
1 The heme group, the subunit which accepts and donates electrons.

The depth cueing uses 36 intensities per color. The initial display is designed to emphasize the central structure of the model. If the model is translated far enough away to be completely visible, the depth cueing will render it virtually invisible. To see the whole model, scale it down (SCAL -) and translate it forward (TRAN +Z) until the perspective, Z-clipping, and depth cueing give an attractive image.

FILES

./hemlib/hemecontrol program
./hemlib/heme[15]data files

HARDWARE CONFIGURATION

A minimum configuration of 16 bitplanes, 1.5 Megabytes of memory, and Z-clipping is required to run heme.