Globins are heme-containing proteins involved in binding and/or transporting oxygen [1]. Almost all globins belong to a large family (see <PDOC00793>), the only exceptions are the following proteins which form a family of their own [2,3,4]:

• Monomeric hemoglobins from the protozoan Paramecium caudatum, Tetrahymena pyriformis and Tetrahymena thermophila.
• Cyanoglobins from the cyanobacteria Nostoc commune and Synechocystis PCC 6803.
• Globins LI637 and LI410 from the chloroplast of the alga Chlamydomonas eugametos.
• Mycobacterium tuberculosis globins glbN and glbO.

These proteins contain a conserved histidine which could be involved in heme-binding. As a signature pattern, we use a conserved region that ends with this residue.