passages.id: split_6_test_557_passage
passages.type: progene_text
passages.text: Human expressed sequence tag clones were identified by sequence similarity to mammalian and yeast oligosaccharide - processing mannosidases , and the full - length coding region of the putative mannosidase homolog was isolated by a combination of 5'-rapid amplification of cDNA ends and direct polymerase chain reaction from human placental cDNA .