Compare cross-species protein alignments to locate stretches of identical amino acids. Conservation can suggest an essential function, lower mutation rate or strong purifying selection.
Golden rice (Oryza sativa, GR) is the generic name given to genetically modified rice that produces beta-carotene (provitamin A). Golden rice was created by transforming rice with the gene coding for the PSY protein (phytoene synthase) from daffodil (Narcissus pseudonarcissus) or from corn (Zea mays).
The picture shows variations of rice.
A White wild-type rice
B Yellow Golden rice expressing the gene coding for PSY from daffodil
C Orange Golden rice expressing the gene coding for PSY from corn
A bioinformatics analysis was performed on the protein PSY transcribed from the gene from corn and from daffodil to obtain the sequence alignment.
On the alignment, identify the longest part of the sequence where the consecutive amino acids are the same.