Characterization of a genomic clone containing the 5′-flanking region of the PECAM-1 gene. The map of Clone 7.2 (5.2 kb) indicates the relative position of selected introns and exons, as well as the restriction sites for several enzymes. As shown, digestion with Pst I, Sph I, or Sma I, alone or in combination with HindIII, yielded the following fragments: Pst I to Pst I (4.7 kb), Sph I to HindIII (2.8 kb), and Sma I to HindIII (1.5 kb). These fragments were subcloned into the vector pGEM7 for sequence analysis.