Structure of the human neutrophil elastase gene

The gene for human neutrophil elastase (NE), a powerful serine protease carried by blood neutrophils and capable of destroying most connective tissue proteins, was cloned from a genomic DNA library of a normal individual. The NE gene consists of 5 exons and 4 introns included in a single copy 4-kilobase segment of chromosome 11 at q14. The coding exons of the NE gene predict a primary translation product of 267 residues including a 29-residue N-terminal precursor peptide and a 20-residue C-terminal precursor peptide. Analysis of the N-terminal peptide sequence suggests it contains a 27-residue "pre" signal peptide followed by a "proN" dipeptide, similar to that of other blood cell lysosomal proteases. The sequences for the mature 218-residue NE protein are included in exons II-V. The 5'-flanking region of the gene includes typical TATA, CAAT, and GC sequences within 61 base pairs (bp) of the cap site. The sequence 1.5 kilobases 5' to exon I contains several interesting repetitive sequences including six tandem repeats of unique 52- or 53-bp sequences. The 5'-flanking region also contains a 19-bp segment with 90% homology to a segment of the 5'-flanking region of the human myeloperoxidase (MPO) gene, a gene also expressed in bone marrow precursor cells and a protein stored in the same neutrophil granules as NE. In addition, like the MPO gene, the NE 5'-flanking region has several regions with greater than or equal to 75% homology to sequences 5' to c-myc, but there is no overlap between the NE-c-myc and MPO-c-myc homologous sequences.     

The nucleotide sequence of the human beta-globin gene

We report the complete nucleotide sequence of the human beta-globin gene. The purpose of this study is to obtain information necessary to study the evolutionary relationships between members of the human beta-like globin gene family and to provide the basis for comparing normal beta-globin genes with those obtained from the DNA of individuals with genetic defects in hemoglobin expression.     

The nucleotide sequence of repetitive monkey DNA found in defective simian virus 40.

DNA fragments containing monkey DNA sequences have been isolated from defective SV40 genomes that carry host sequences in place of portions of the SV40 genome. The fragments were isolated by restriction endonuclease cleavage and contain segments homologous to sequences in both the highly repetitive and unique (or less repetitive) classes of monkey DNA. The complete nucleotide sequence of one such fragment [151 base pairs (bp)] predominantly homologous to the highly reiterated class of monkey DNA was determined using both RNA and DNA sequencing methods. The nucleotide sequence of this homogeneous DNA segment does not contain discernible multiple internal repeating units but only a few short oligonucleotide repeats. The reiteration frequency of the sequence in the monkey genome is >10⁶. Digestion of total monkey DNA (from uninfected cells) with endonuclease R Hind III produces relatively large amounts of discrete DNA fragments that contain extensive regions homologous to the fragment isolated from the defective SV40 DNA.A second fragment, also containing monkey sequences, was isolated from the same defective substituted SV40 genome. The nucleotide sequence of the 33 bp of this second fragment that are contiguous to the 151 bp fragment has also been determined.The sequences in both fragments are also present in other, independently derived, defective substituted SV40 genomes.     

Trypanosoma (Schizotrypanum) cruzi: repetitive DNA sequence evolution in three geographically distinct isolates

1. Middle-repetitive DNA sequences were analyzed by molecular hybridization to determine both the extent of complementarity and time of evolutionary divergence between isolates of Trypanosoma cruzi from Argentina, Mexico, or Venezuela. 2. Although molecular hybridizations showed no significant difference between the middle-repetitive DNAs of the Mexican and Venezuelan isolates, there was a 2.7% base pair mismatch in hybrid molecules formed by association of strands from both the Mexican and Argentine isolates. 3. Using the rates for divergence of middle-repetitive DNA in sea urchins, the Mexican and Argentine isolates were estimated to have diverged approximately 20-25 million years ago. 4. Analysis of the kinetics for the DNA hybridizations indicates that only minor amplifications of specific gene sequences or changes in the complexity of the genomes could have occurred during the divergence of the three isolates studied.     

Complete nucleotide sequence of the human corticotropin-beta-lipotropin precursor gene.

The nucleotide sequence of an 8658-base-pair human genomic DNA segment containing the entire corticotropin-beta-lipotropin precursor gene has been determined, and some sequence features of the gene and its flanking regions have been analysed. The gene is composed of 7665 base pairs including two introns of 3708 and 2886 base pairs. Comparison of the 5'-flanking sequences of the human, bovine and mouse corticotropin-beta-lipotropin precursor genes reveals the presence of a highly conserved region, which contains sequences of 14-15 base pairs homologous with sequences located upstream of the mRNA start site of other glucocorticoid-regulated genes.     

Clustered and interspersed repetitive DNA sequence family of Chironomus. The nucleotide sequence of the Cla-elements and of various flanking sequences

The nucleotide sequence of more than 30 cloned members of the clustered and interspersed repetitive Cla-sequence family present in the genome of various chironomids has been determined. In four cloned Cla-element clusters, the 5' and 3'-flanking sequences including the junctions between the Cla-element clusters and the flanking sequences were also sequenced. The repetitive Cla-elements, which are able to transpose under certain circumstances, have a monomer length ranging from 110 to 119 base-pairs, are very A + T-rich (greater than 80% A + T) and display numerous palindromic sequences. The Cla-elements are organized in small (4 elements) to medium-sized (greater than 30 elements) tandem repetitive clusters, which are dispersed over more than 200 sites of the chromosomes of Chironomus thummi thummi, including the non-transcribed spacer of the ribosomal DNA repeating unit. The tandem repetitive Cla-elements show anomalous behaviour during high-percentage polyacrylamide gel electrophoresis, indicating a bent or globular conformation. The flanking sequences are also repetitive, but the sequenced parts did not reveal any tandem repetitive arrangement. Near the junctions of the Cla-element clusters and the flanking sequences, short duplications are found, ranging from 5 to 12 bases, present in both sides of the Cla-element clusters. The Cla-elements might be involved in the hybrid dysgenesis phenomenon that is observed after crossings between the two subspecies Ch. th. thummi and Ch. th. piger.     

DNA nucleotide sequence analysis of the immediate-early gene of pseudorabies virus.

The complete DNA sequence coding for the immediate-early protein (IE180) of pseudorabies virus was determined. The coding region of IE180 is 4380 nucleotides for 1460 amino acid residues. G+C content of the non-coding portion of the IE gene is 70.3% while the G+C content of the coding portion is considerably higher at 80.1%. Correspondingly, codons consisting mainly of Gs and Cs are favoured. Clusters of amino acid homologies are observed among IE180 of pseudorabies virus, ICP4 of herpes simplex virus type-1 and IE140 of varicella-zoster virus, and are organized similarly in all three polypeptides. Functions exhibited by IE180 are assigned, tentatively, to structural domains of the molecule by analogy to the HSV-1 ICP4 polypeptide.