THE HUMAN ALPHA-2(XI) COLLAGEN GENE (COL11A2) - COMPLETION OF CODING INFORMATION, IDENTIFICATION OF THE PROMOTER SEQUENCE, AND PRECISE LOCALIZATION WITHIN THE MAJOR HISTOCOMPATIBILITY COMPLEX REVEAL OVERLAP WITH THE KE5 GENE

Type XI collagen, a fibril-forming collagen, is important for the inte grity and development of the skeleton because mutations in the genes e ncoding its consituent alpha chains have been found in some osteochond rodysplasias. We provide data that complete information for the coding sequence of human alpha 2(XI) procollagen, with details of the promot er region and intron-exon organization at the 5' and 3' ends of the ge ne (COL11A2), including the transcription start and polyadenylation si tes. COL11A2 is 30.5 kb with a minimum of 62 exons, differing from oth er reported fibrillar collagen genes because the amino propeptide is e ncoded by 14 not 5 to 8 exons. But exon numbers for the carboxy propep tide and 3'-untranslated region are conserved. The promoter region of COL11A2 lacks a TATA box but is GC-rich with two potential SP1 binding sites. Mouse alpha 2(XI) collagen mRNAs undergo complex alternative s plicing involving three amino-terminal propeptide exons but only one o f these has been reported for COL11A2. We have located these missing h uman exons and have identified splice signals that point to additional splice variants. We have precisely mapped COL11A2 within the major hi stocompatibility complex on chromosome 6. The retinoid X receptor beta (RXR beta) gene is located 1.1 kb upstream of COL11A2. KE5, previousl y thought to be a distinct transcribed gene sequence, was mapped withi n COL11A2 in the alternatively spliced region, raising the question wh ether KE5 and COL11A2 are separate genes. (C) 1996 Academic Press, Inc .