Chapter 19
Biochemistry and Molecular Biology
of the Enzyme ACC Deaminase
Shimaila Ali and Bernard R. Glick
Abstract Throughout their development processes over many millions of years,
plants have adopted a number of mechanisms whereby they could either modify
themselves (genotypically and/or phenotypically), or their interaction with their
surrounding environment. The utilization of such strategies, which is a direct
consequence of plant–microbe interactions, can help plants to grow and adapt better
in searching and utilizing potential energy resources, in overcoming various environmental abiotic stresses, and in fighting against plant pathogens. The functioning
of the microbial enzyme 1-aminocyclopropane-1-carboxylase (ACC) deaminase is
believed to be one of the key mechanisms that is provided by soil microbes that
plants have benefitted from under a variety of environmental conditions. The
1-aminocyclopropane-1-carboxylase deaminase is a multimeric enzyme that belongs
to the tryptophan synthase beta superfamily of enzymes that requires pyridoxal
phosphate as a cofactor and acts to cleave ACC, the immediate precursor of ethylene
in all higher plants. ACC deaminase is particularly important in lowering inhibitory
plant stress ethylene levels that form as a consequence of various environmental
stresses, both abiotic and biotic, thereby significantly facilitating plant growth,
especially under adverse conditions. The enzyme ACC deaminase has been reported
to be present in various groups of Biota including all three domains of life, i.e.,
Archaea, Bacteria, and Eukarya. The activity of the enzyme is primarily organism
specific, but environmental factors also affect its activity. Here, the phylogeny of
organisms encoding this enzyme and the biochemistry of ACC deaminase from
various sources is documented and compared. The possible transcriptional regulatory mechanisms of this enzyme in various bacteria are also described herein, with
the best-studied and most common mechanisms elaborated in detail. The fundamental information summarized here provides an important step toward understanding
S. Ali (*)
A&L Biologicals, Agroecological Research Services Centre, London, ON, Canada
e-mail: shimaila@alcanada.com; s9rashid@uwaterloo.ca
B. R. Glick (*)
Department of Biology, University of Waterloo, Waterloo, ON, Canada
e-mail: glick@uwaterloo.ca
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_19
365
Biochemistry and Molecular Biology
of the Enzyme ACC Deaminase
Shimaila Ali and Bernard R. Glick
Abstract Throughout their development processes over many millions of years,
plants have adopted a number of mechanisms whereby they could either modify
themselves (genotypically and/or phenotypically), or their interaction with their
surrounding environment. The utilization of such strategies, which is a direct
consequence of plant–microbe interactions, can help plants to grow and adapt better
in searching and utilizing potential energy resources, in overcoming various environmental abiotic stresses, and in fighting against plant pathogens. The functioning
of the microbial enzyme 1-aminocyclopropane-1-carboxylase (ACC) deaminase is
believed to be one of the key mechanisms that is provided by soil microbes that
plants have benefitted from under a variety of environmental conditions. The
1-aminocyclopropane-1-carboxylase deaminase is a multimeric enzyme that belongs
to the tryptophan synthase beta superfamily of enzymes that requires pyridoxal
phosphate as a cofactor and acts to cleave ACC, the immediate precursor of ethylene
in all higher plants. ACC deaminase is particularly important in lowering inhibitory
plant stress ethylene levels that form as a consequence of various environmental
stresses, both abiotic and biotic, thereby significantly facilitating plant growth,
especially under adverse conditions. The enzyme ACC deaminase has been reported
to be present in various groups of Biota including all three domains of life, i.e.,
Archaea, Bacteria, and Eukarya. The activity of the enzyme is primarily organism
specific, but environmental factors also affect its activity. Here, the phylogeny of
organisms encoding this enzyme and the biochemistry of ACC deaminase from
various sources is documented and compared. The possible transcriptional regulatory mechanisms of this enzyme in various bacteria are also described herein, with
the best-studied and most common mechanisms elaborated in detail. The fundamental information summarized here provides an important step toward understanding
S. Ali (*)
A&L Biologicals, Agroecological Research Services Centre, London, ON, Canada
e-mail: shimaila@alcanada.com; s9rashid@uwaterloo.ca
B. R. Glick (*)
Department of Biology, University of Waterloo, Waterloo, ON, Canada
e-mail: glick@uwaterloo.ca
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_19
365