Compositions and methods for conferring herbicide resistance or tolerance to bacteria, plants, plant cells, tissues and seeds are provided. Compositions include polynucleotides encoding herbicide resistance or tolerance polypeptides, vectors comprising those polynucleotides, and host cells comprising the vectors. The nucleotide sequences of the invention can be used in DNA constructs or expression cassettes for transformation and expression in organisms, including microorganisms and plants. Compositions also include transformed bacteria, plants, plant cells, tissues, and seeds. In particular, isolated polynucleotides encoding glyphosate resistance or tolerance polypeptides are provided, particularly polypeptide variants of SEQ ID NO:2 and 4. Additionally, amino acid sequences corresponding to the polynucleotides are encompassed. In particular, the present invention provides for isolated polynucleotides containing nucleotide sequences encoding the amino acid sequence shown in SEQ ID NO:7-28, or the nucleotide sequence set forth in SEQ ID NO:29 or 30.