The gene for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is located close to the gene for the large subunit in the cyanobacterium Anacystis nidulans 6301.

The gene for the small subunit (SS) of ribulose-1,5-bisphosphate carboxylase/oxygenase from a cyanobacterium, Anacystis nidulans 6301, has been cloned and subjected to sequence analysis. The SS coding region is located close to and downstream from the large subunit (LS) coding region on the same DNA strand. The spacer region between the LS and the SS coding regions contains 93 base pairs (bp), and has no promoter-like sequences. The coding region of A. nidulans SS gene contains 333 bp (111 codons). The deduced amino acid sequence of the A. nidulans SS protein shows 40% homology with those of higher plants.     

Genes downstream from pucB and pucA are essential for formation of the B800-850 complex of Rhodobacter capsulatus.

The formation of the light-harvesting complex B800-850 (LH-II) of Rhodobacter capsulatus requires, in addition to the synthesis of the polypeptides alpha and beta (the gene products of pucA and pucB), the synthesis of bacteriochlorophyll and carotenoids and the expression of at least one gene localized downstream from the pucBA operon. This was concluded from the observation that a Tn5 insertion downstream from pucBA inhibited the formation of the LH-II complex and the formation of the pucBA mRNA. The Tn5 insertion point was mapped and found to be over 500 base pairs (bp) downstream from the end of the pucA gene, suggesting the presence of additional puc genes. A region of about 3,000 bp including the pucB and pucA genes and DNA downstream from pucA was sequenced and found to contain three open reading frames (ORFs C, D, and E). The polypeptide deduced from the first ORF (C) contains 403 amino acids with strongly hydrophobic stretches and one large and three small hydrophilic domains carrying many charged residues. The other two ORFs contain 113 (D) and 118 (E) codons. The amino acid sequences of the N terminus and two tryptic peptides of an alkaline-soluble Mr-14,000 subunit of the isolated LH-II complex were identical with the deduced amino acid sequence of ORF E.     

Structure of Escherichia coli dnaC. Identification of a cysteine residue possibly involved in association with dnaB protein

The nucleotide sequence of the Escherichia coli dnaC gene and the primary structure of the dnaC protein were determined. The NH2-terminal amino acid sequence of the dnaC protein matched that predicted from the nucleotide sequence of the 735-base pair coding region. The dnaC gene lacks characteristic promoter structures; neither the "Pribnow box" nor the "-35 sequence" was detected within 222 base pairs upstream from the initiator ATG codon. There is, however, a typical Shine-Dalgarno sequence 7-10 base pairs before the ATG codon. An upstream open reading frame, separated by just 2 base pairs from the coding region of dnaC, encodes the COOH-terminal half of the dnaT product (protein i; Masai, H., Bond, M. W., and Arai, K. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 1256-1260). The dnaC protein contains 245 amino acids with a calculated molecular weight of 27,894 consistent with the observed value (29,000). Similar to dnaG and dnaT, dnaC uses several minor codons; the significance of these minor codons to the low level expression of the protein product in E. coli cells remains to be determined. The in vitro site-directed mutagenesis method was employed to determine the functional region involved in interaction with dnaB protein. The first cysteine residue located in the NH2-terminal region of the dnaC protein (Cys69) was shown to be important for this activity. Overall sequence homology between dnaC protein and lambda P protein, functionally analogous to the dnaC protein in the lambda phage DNA replication, is not extensive. There are, however, several short stretches of homologous regions including the NH2-terminal eight amino acids and the Cys78 region of dnaC protein.     

Genetic and physical analysis of the thioredoxin (trxA) gene of Escherichia coli K-12

The trxA gene of Escherichia coli K-12 has been cloned into multicopy plasmids on DNA fragments of varying sizes. The smallest of these was a 1-kb fragment resulting from partial digestion with Sau3A (pBHK10). The complete nucleotide sequence of the trxA gene and its promoter was determined. Comparison of the DNA sequence with the published amino acid sequence revealed the inversion of two amino acid pairs and the possibility of a leader peptide 18 amino acids in length. Three-factor P1 transductional crosses and physical mapping experiments have determined a map order of ilv-trxA-uvrD-corA-metE.     

Sequence conservation and structural organization of the glycerol-3-phosphate dehydrogenase promoter in mice and humans.

Cloned segments of the mouse glycerol-3-phosphate dehydrogenase (GPDH) gene, Gdc-1, were used to screen a human library. Human clones obtained spanned 25 kilobases of genomic DNA containing the human GPDH gene, GPD1. The 4 kb of sequence obtained from the 5'-flanking region and first exon of GPD1 was compared with the corresponding mouse sequence. Both sequences share a HindIII site located in what has proven to be the highly conserved 3' untranslated region of an upstream gene of unknown function, D15Kzl. The 3.6-kilobase segment of mouse DNA located between D15Kzl and Gdc-1 was provisionally termed the GPDH promoter. Alignment of the mouse promoter with the corresponding human sequence revealed two conserved domains. An upstream distal promoter region is approximately 900 base pairs in length. A downstream or proximal promoter region consists of approximately 300 base pairs immediately upstream of a TATA-like box and contains the fat-specific elements 1 and 2. Analysis of the chromatin structure of the Gdc-1 promoter revealed four DNase I-hypersensitive sites. They were present in DNA of liver and brown fat, in which GPDH expression is high, but were absent in DNA of spleen, in which GPDH expression is low. Methylation studies of the promoter showed it to be heavily methylated in sperm. However, the DNA from each adult somatic tissue had a unique distribution of nonmethylated sites and could easily be identified by its methylation pattern. These data suggest a structural model of the promoter that explains how Gdc-1 expression is differentially regulated in many types of cells.     

Isolation and characterization of the bovine corticotropin/beta-lipotropin precursor gene

The entire bovine corticotropin/beta-lipotropin precursor gene has been isolated as a set of overlapping genomic DNA fragments which extend over a length of approximately 17000 base pairs. Restriction mapping of the cloned DNA fragments and nucleotide sequence analysis of the whole mRNA-coding segments and their surrounding regions have established that the corticotropin/beta-lipotropin precursor gene is approximately 7300-base-pairs long and contains two intervening sequences; one with an approximate length of 4000 base pairs is located within the segment encoding the 5'-untranslated region of the mRNA, and the other with an approximate length of 220 base pairs interrupts the protein-coding sequence near the signal peptide region. Sequence analysis of more than 200 base pairs preceding the proximal end of the corticotropin/beta-lipotropin precursor gene has revealed a 'Hogness box' and a variant of the model sequence d(G-G-TC-C-A-A-T-C-T) as well as palindrome structures as observed in other eukaryotic genes. Furthermore, some sequence similarities in the 5'-flanking region are found between the corticotropin/beta-lipotropin precursor gene and the mouse alpha-globin and beta-globin genes, all of which are negatively regulated by glucocorticoids. At least four homologous repetitive sequences are distributed at 3000-5000-base-pair distances in the corticotropin/beta-lipotropin precursor gene region; two such sequences are located in the 5'-flanking region, and one within each intervening sequence. Blot hybridization analysis of bovine pituitary nuclear RNA has indicated that the entire corticotropin/beta-lipotropin precursor gene is transcribed into a primary hnRNA product, which is then spliced to form the mature mRNA.