Determination of Inosine Monophosphate and Guanosine Monophosphate

2015 ◽  
pp. 553-568
Keyword(s):  
Guanosine Monophosphate ◽  
Inosine Monophosphate

scholarly journals The mycobacterial guaB1 gene encodes a guanosine 5'-monophosphate reductase with a cystathione-β-synthase domain

2021 ◽  
Author(s):  
Zdeněk Knejzlík ◽  
Michal Doležal ◽  
Klára Herkommerová ◽  
Kamila Clarova ◽  
Martin Klima ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
De Novo ◽  
Gene Knockout ◽  
Guanosine Monophosphate ◽  
Inosine Monophosphate Dehydrogenase ◽  
Purine Salvage ◽  
Inosine Monophosphate ◽  
Salvage Pathways ◽  
Cbs Domains ◽  
Purine Salvage Pathways

Purine metabolism plays a pivotal role in bacterial life cycle, however, regulation of the de novo and purine salvage pathways have not been extensively detailed in mycobacteria. By gene knockout, biochemical and structural analyses, we identified Mycobacterium smegmatis (Msm) and Mycobacterium tuberculosis (Mtb) guaB1 gene product as a novel type of guanosine 5'-monophosphate reductase (GMPR), which recycles guanosine monophosphate to inosine monophosphate within the purine salvage pathway and contains cystathione β-synthase (CBS) domains with atypical orientation in the octamer. CBS domains share a much larger interacting area with a conserved catalytic domain in comparison with the only known CBS containing protozoan GMPR and closely related inosine monophosphate dehydrogenase structures. Our results revealed essential effect of pH on allosteric regulation of Msm GMPR activity and oligomerization with adenine and guanosine nucleotides binding to CBS domains.Bioinformatic analysis indicated the presence of GMPRs containing CBS domains across the entire Actinobacteria phylum.

The raspberry locus of Drosophila melanogaster includes an inosine monophosphate dehydrogenase like coding sequence

Genome ◽  
1994 ◽  
Vol 37 (2) ◽  
pp. 333-344 ◽  
Author(s):  
D. Nash ◽  
S. Hu ◽  
N.-J. Leonard ◽  
S. Y. K. Tiong ◽  
D. Fillips
Keyword(s):  
Drosophila Melanogaster ◽  
Guanosine Monophosphate ◽  
P Element ◽  
Inosine Monophosphate Dehydrogenase ◽  
Ras Gene ◽  
Inosine Monophosphate ◽  
Lethal Mutations ◽  
Eye Colour ◽  
Lethal Allele ◽  
Monophosphate Dehydrogenase

DNA from the raspberry gene of Drosophila melanogaster has been cloned through P-element tagging of a dysgenically induced lethal allele. A transcribed DNA segment adjacent to the P insert encodes an amino acid sequence that is similar to known inosine monophosphate dehydrogenase (IMPDH) sequences. Further dysgenically induced lethals and all four known spontaneous ras eye-colour mutations have changes in the DNA either within or just upstream from the transcribed region. Identification of IMPDH as a probable product of the ras gene is compatible with the finding of an allele that requires dietary guanosine (GR), since the enzyme mediates the first of two biosynthetic steps leading from inosine monophosphate (IMP) to guanosine monophosphate (GMP). However, other auxotrophic mutants at the locus remain unexplained by the finding. The results further suggest that GMP synthesis from IMP is an essential process, despite the capacity of the fly for salvage synthesis of GMP from GR. Consideration of the phenotypes associated with mutants at the ras locus suggests that IMPDH activity is regulated in a tissue-specific manner.Key words: inosinate dehydrogenase, IMPDH, guanosine auxotrophy, purine synthesis, raspberry mutants, lethal mutations, Drosophila melanogaster.

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