(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Viridiplantae: NE > Streptophyta: NE > Streptophytina: NE > Embryophyta: NE > Tracheophyta: NE > Euphyllophyta: NE > Spermatophyta: NE > Magnoliophyta: NE > Mesangiospermae: NE > Liliopsida: NE > Petrosaviidae: NE > commelinids: NE > Poales: NE > Poaceae: NE > PACMAD clade: NE > Panicoideae: NE > Andropogonodae: NE > Andropogoneae: NE > Tripsacinae: NE > Zea: NE > Zea mays: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MPSSAQVLLCLAAVLAAAAATTAEAHSQCLDNPPDRSIHGRQLAEAGEVV HDLPGGLRAYVSGAASSSRAVVLASDVFGYEAPLLRQIADKVAKAGYFVV VPDFLKGDYLDDKKNFTEWLEAHSPVKAAEDAKPLFAALKKEGKSVAVGG YCWGGKLSVEVGKTSDVKAVCLSHPYSVTADDMKEVKWPIEILGAQNDTT TPPKEVYRFVHVLRERHEVPYYAKIFQGVEHGFACRYNTTDPFAVKTAET ALAYMVSWFNKHLN
We present a large portion of the transcriptome of Zea mays, including ESTs representing 484,032 cDNA clones from 53 libraries and 36,565 fully sequenced cDNA clones, out of which 31,552 clones are non-redundant. These and other previously sequenced transcripts have been aligned with available genome sequences and have provided new insights into the characteristics of gene structures and promoters within this major crop species. We found that although the average number of introns per gene is about the same in corn and Arabidopsis, corn genes have more alternatively spliced isoforms. Examination of the nucleotide composition of coding regions reveals that corn genes, as well as genes of other Poaceae (Grass family), can be divided into two classes according to the GC content at the third position in the amino acid encoding codons. Many of the transcripts that have lower GC content at the third position have dicot homologs but the high GC content transcripts tend to be more specific to the grasses. The high GC content class is also enriched with intronless genes. Together this suggests that an identifiable class of genes in plants is associated with the Poaceae divergence. Furthermore, because many of these genes appear to be derived from ancestral genes that do not contain introns, this evolutionary divergence may be the result of horizontal gene transfer from species not only with different codon usage but possibly that did not have introns, perhaps outside of the plant kingdom. By comparing the cDNAs described herein with the non-redundant set of corn mRNAs in GenBank, we estimate that there are about 50,000 different protein coding genes in Zea. All of the sequence data from this study have been submitted to DDBJ/GenBank/EMBL under accession numbers EU940701-EU977132 (FLI cDNA) and FK944382-FL482108 (EST).
        
Title: Endo-1,3;1,4-beta-glucanase from coleoptiles of rice and maize: role in the regulation of plant growth Thomas BR, Inouhe M, Simmons CR, Nevins DJ Ref: Int J Biol Macromol, 27:145, 2000 : PubMed
The Matrix Polymer Hydrolysis Model for regulation of growth in plants is based on the simultaneous hydrolysis and incorporation of new glucans into the cell wall observed in growing plant tissues. The inhibition of growth in rice coleoptile tissues treated with glucanase antibodies confirms similar results observed previously in maize coleoptiles and provides direct evidence for a role of glucanase in control of plant growth. Analysis of two-maize coleoptile endo-glucanase ESTs shows that these sequences are not related to any other previously known family of glycosyl hydrolase. Thus, the coleoptile endo-glucanase enzyme should be classified as a new enzyme group (E.C. 3.2.1.xx). These discoveries enable new initiatives for further investigation of the glucanase role in control of plant growth.
        
Title: Polypeptide characteristics and immunological properties of exo- and endoglucanases purified from maize coleoptile cell walls. Inouhe M, Hayashi K, Nevins DJ Ref: J Plant Physiol, 154:334, 1999 : PubMed
Cereal coleoptile cell walls have exo- and endoglucanases capable of mediating the hydrolysis of non-cellulosic beta-(l,3)(l,4)-glucan in situ. A purified exoglucanase (EC 3.2.1.58) resolved as a single band at 73.5 kDa, while endoglucanase isozymes consistently appeared as two bands at 32.9 and 34.3 kDa when subjected to SDS-PAGE. HPLC analysis of the native proteins by gel-permeation chromatography revealed molecular weights of ca. 55 and 29 kDa for the exo- and endoglucanases, respectively. The exoglucanase has an isoelectric focusing point at pi 7.2 and the endoglucanase isozymes appeared as two major bands, one at pi 7.8 and another at 7.3. Deglycosylation of the native proteins followed by SDS-PAGE demonstrated that sugars accounted for ca. 6.5 % of the exoglucanase and were 12.5 and 8.8 % of the two endoglucanase isozymes, respectively. After deglycosylation the two endoglucanases converged at 30.0 kDa, suggesting polypeptide homology and that divergence in electrophoretic mobility was a consequence of glycosylation. Antibodies raised against intact exo- and endoglucanases recognized the polypeptide of the corresponding enzymes, irrespective of glycosylation. The N-terminal amino acid sequence supported the conclusion that the exo- and endoglucanase have different polypeptide structures.