<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE amino-acid SYSTEM "aminoacids.dtd">
<amino-acid>
   <name>Cysteine</name>
   <abbreviation>cys</abbreviation>
   <symbol>c</symbol>
   <molecular-formula>C3H7NO2S</molecular-formula>
   <molecular-weight>121.15</molecular-weight>
   <isoelectric-point>5.02</isoelectric-point>
   <CAS-registry-number>52-90-4</CAS-registry-number>
</amino-acid>
