| The mixture was later solidified by means of a surface agar solution containing traces of histidine and biotin. |
| The active site of trypsin involves a catalytic triad consisting of the amino acids serine, histidine and aspartic acid. |
| Due to the acid environment in the P. falciparum food vacuole, all histidine residues in the model were modeled using the AMBER HIP residue. |
| The GPP protein also contains several regions rich in alanine, proline, histidine, and glutamine. |
| In addition to histidine and biotin, the top agar contained minimal tryptophan to support E.coli growth. |
| Starvation for histidine derepresses the entire operon, the longest then known. |
