A cDNA clone designated Ag169 was isolated from a λAmp3 expression library of P. falciparum isolate FC27 on the basis of its reaction with sera from adults living in Papua New Guinea. Isolation of a 2152 bp chromosomal DraI fragment from FC27 and then a ∼ 4 kb overlapping AluI fragment allowed determination of the sequence of a gene encoding a polypeptide. As the mature polypeptide predicted contains 26% glutamic acid, it is termed glutamic acid-rich protein (GARP). It has a predicted molecular weight of 80 463 (precursor) or 77 046 (mature protein). The GARP gene was present in each of 3 isolates tested (FC27, NF7 and K1) and no polymorphisms in EcoRI, DraI or HinfI restriction sites were detected by Southern blotting. The gene is located near the right end of chromosome 1.