CREATE TABLE table_21137 ("Species" TEXT, "Species common name" TEXT, "NCBI Accession Number  ( mRNA/Protein ) " TEXT, "Length  ( bp/aa ) " TEXT, "Protein Identity" TEXT)

What is the protein identity with a length of 5304bp/377aa?
SELECT "Protein Identity" FROM table_21137 WHERE "Length (bp/aa)" = '5304bp/377aa'
SELECT "Protein Identity" FROM "table_21137" WHERE "Length (bp/aa)" = '5304bp/377aa'