Methylibium petroleiphilum strain PM1 uses various petroleum products including the fuel additive methyl tert-butyl ether and straight chain and aromatic hydrocarbons as sole carbon and energy sources. It has two operons, dmpI and dmpII, that code for the enzymes in a pair of parallel meta-fission pathways. In order to understand the roles of the pathways, the 4-oxalocrotonate tautomerase (4-OT) isozyme from each pathway was characterized. Tautomerase I and tautomerase II have the lowest pairwise sequence identity (35%) among the isozyme pairs in the parallel pathways, and could offer insight into substrate preferences and pathway functions. The kinetic parameters of tautomerase I and tautomerase II were determined using 2-hydroxymuconate and 5-(methyl)-2-hydroxymuconate. Both tautomerase I and tautomerase II process the substrates, but with different efficiencies. Crystal structures were determined for both tautomerase I and tautomerase II, at 1.57 and 1.64Å resolution, respectively. The backbones of tautomerase I and tautomerase II are highly similar, but have distinct active site environments. The results, in combination with those for other structurally and kinetically characterized 4-OT isozymes, suggest that tautomerase I catalyzes the tautomerization of both 2-hydroxymuconate and alkyl derivatives, whereas tautomerase II might specialize in other aromatic hydrocarbon metabolites.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3788618PMC
http://dx.doi.org/10.1016/j.abb.2013.06.016DOI Listing

Publication Analysis

Top Keywords

tautomerase tautomerase
20
tautomerase
13
methylibium petroleiphilum
8
petroleiphilum strain
8
strain pm1
8
structural kinetic
4
kinetic characterization
4
characterization 4-oxalocrotonate
4
4-oxalocrotonate tautomerases
4
tautomerases methylibium
4

Similar Publications

Background: In-feed antibiotic growth promoters (AGPs) have been a cornerstone in the livestock industry due to their role in enhancing growth and feed efficiency. However, concerns over antibiotic resistance have driven a shift away from AGPs toward natural alternatives. Despite the widespread use, the exact mechanisms of AGPs and alternatives are not fully understood.

View Article and Find Full Text PDF

Consisting of more than 11,000 members distributed over five families, the tautomerase superfamily (TSF) is a large collection of proteins with diverse biological functions. While much attention has been given to individual TSF enzymes, a majority remain structurally and functionally uncharacterized. Given its large size, studying a representative member of each family offers a viable approach for extracting mechanistic insights applicable to the entire superfamily.

View Article and Find Full Text PDF

AbstractHormones can induce trait development in one species yet have no effect on the same trait in a closely related species, but the mechanisms underlying these differences are unclear. Here, we compare two closely related lizard species to explore the cellular mechanisms associated with the evolutionary loss of hormonally mediated ventral coloration. The eastern fence lizard () has sexually dimorphic blue and black ventral coloration that develops when maturational increases in androgens induce melanin synthesis in males.

View Article and Find Full Text PDF

This review consolidates a decade of research on fumarylacetoacetate hydrolase domain containing protein 1 (FAHD1), a mitochondrial oxaloacetate tautomerase and decarboxylase with profound implications in cellular metabolism. Despite its critical role as a regulator in mitochondrial metabolism, FAHD1 has remained an often-overlooked enzyme in broader discussions of mitochondrial function. After more than 12 years of research, it is increasingly clear that FAHD1's contributions to cellular metabolism, oxidative stress regulation, and disease processes such as cancer and aging warrant recognition in both textbooks and comprehensive reviews.

View Article and Find Full Text PDF

Palmitoyl copper peptide and acetyl tyrosine complex enhances melanin production in both A375 and B16 cell lines.

Biochem Biophys Res Commun

January 2025

State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; Marine Biomedical Science and Technology Innovation Platform of Lin-gang Special Area, No.4, Lane 218, Haiji Sixth Road, Shanghai, 201306, China. Electronic address:

Copper peptide, a low molecular weight peptide composed of glycyl-L-histidyl-l-lysine-copper, possesses anti-aging, anti-inflammatory, and wound healing properties. In this study, we investigated the effects of a combination agent CP-AcT, composed of palmitoyl copper peptide (pal-GHK-Cu) and acetyl tyrosine (N-Acetyl-l-tyrosine), on melanin production in the human malignant melanoma cell line A375 and the mouse melanoma cell line B16. Firstly, the cytotoxicity of CP-AcT at various concentrations (0-8 μg/mL) on HaCat, HFF, A375, and B16 cells was evaluated.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!